feat(webui): Gitea issue and PR linkage console (Closes #645)

Add a Phase 3 read-only console that resolves issue↔PR linkage with
evidence (closes keyword, branch marker, body mention), surfaces the
latest canonical handoff for a focused thread, and deep-links to Gitea
only under the admin reveal opt-in.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

docs/webui-local-dev.md

@@ -80,6 +80,8 @@ status, onboarding checklist state, and the fail-closed error payloads (#635).
 | `/sessions` | Runtime and session view (#641) — health + inventory sessions/namespaces/worktrees |
 | `/api/sessions` | JSON export for the runtime/session view |
 | `/api/v1/sessions` | Versioned alias of `/api/sessions` |
+| `/gitea` | Gitea issue↔PR linkage console (#645) — both directions, with the evidence for each edge |
+| `/api/v1/gitea/linkage` | JSON linkage export; `502` when the read could not be answered |
 | `/inventory` | Phase 1 shell stub — unified inventory (backed by #636) |
 | `/timeline` | Phase 1 shell stub — workflow event timeline |
 | `/policy` | Phase 1 shell stub — capability/role policy placeholder |
@@ -327,6 +329,68 @@ Honesty rules specific to this view:
   The write-time redactor is a narrow denylist and is not relied on. The field
   itself is kept — it is the `#630` evidence naming which daemon was killed.
 
+## Gitea issue/PR linkage (#645)
+
+`/gitea` is the Phase 3 read-only linkage console: which PR carries which issue,
+which issues are claimed by more than one PR, and what the latest Canonical
+Thread Handoff on a thread said. Gitea remains the source of truth — this
+surface reads it and never writes to it. There is no issue/PR editor, no review,
+and no merge control.
+
+Query parameters (all optional):
+
+| Parameter | Meaning |
+|-----------|---------|
+| `project` | Registry project id to scope the read (default: first registry entry) |
+| `state` | `open` (default) or `all`; `all` widens the window to merged/closed items, where a landed edge lives |
+| `issue=N` / `pr=N` | Focus one thread and load *its* latest canonical handoff |
+
+`GET /api/v1/gitea/linkage` returns the same model as JSON
+(`schema_version: 1`). It answers `502` when the read could not be answered, so
+an automated consumer cannot mistake a fail-closed payload for "no links exist".
+The HTML page always answers `200` and renders the reason instead — an operator
+view must show why a read failed rather than withhold the page.
+
+### How an edge is found
+
+Each edge carries the evidence that produced it, strongest first:
+
+| Evidence | Meaning |
+|----------|---------|
+| `closes_keyword` | The PR title or body declares `closes/fixes/resolves #N`. Gitea itself acts on this keyword. |
+| `branch_marker` | The PR head branch carries the canonical `(fix\|feat\|docs\|chore)/issue-N-…` marker minted by the issue lock. |
+| `body_reference` | The PR body mentions `#N` with no closing keyword. A mention is not a claim to close. |
+
+Only closing and branch-marker edges populate the **issue → PR** direction: a
+bare mention is a cross-link, and counting it as ownership would invent
+contested issues out of ordinary references. The mention stays visible on the
+**PR → issue** side, labelled as such. A PR whose two strongest edges tie is
+flagged `ambiguous`; an issue claimed by two PRs is flagged `contested`.
+
+### Honesty rules specific to this view
+
+* **A partial read never reads as an absence.** Linkage is a claim about the
+  loaded window only. When pagination did not complete, every empty edge cell
+  renders `none found (partial inventory)` rather than `none`, and the JSON
+  carries `inventory_complete: false` plus per-row `links_authoritative: false`.
+* **A failed read renders no table at all.** Missing credentials, an unknown
+  project, or a fetch error produce `ok: false` with a reason. An empty linkage
+  table would assert that no issue is linked to any PR, which such a read is not
+  in a position to claim.
+* **Handoffs are loaded, never assumed.** CTH comments are thread-scoped, so
+  only the focused issue or PR has its comments fetched. Every other row reports
+  `not_loaded` with the reason; a thread whose comments *were* loaded and carried
+  no CTH says exactly that. A comment-source failure degrades the handoff alone —
+  the linkage tables still render.
+* **Unrecognised handoff headings are reported, not republished.** A `## CTH:`
+  heading outside `CTH_TYPES` renders as `unrecognized`.
+* **Redaction precedes display.** Titles, labels, handoff fields, and error
+  reasons pass through `webui.console_redaction` before serialization, and the
+  page HTML-escapes everything it renders.
+* **Deep links are opt-in.** A link out to the Gitea web UI appears only when
+  `GITEA_MCP_REVEAL_ENDPOINTS=1` is set server-side, matching how the MCP tools
+  gate URL exposure. Item numbers stay usable without it.
+
 ## System-health dashboard (#639)
 
 `/system-health` renders the same snapshot the `/api/v1/system/health` API

gitea_mcp_server.py

@@ -9552,15 +9552,13 @@ def gitea_edit_pr(
     if closing:
         gate_reasons = _profile_operation_gate("gitea.pr.close")
         if gate_reasons:
-            return {
+            return _build_operation_gate_refusal(
-                "success": False,
+                "gitea.pr.close",
-                "performed": False,
+                gate_reasons,
-                "pr_number": pr_number,
+                pr_number=pr_number,
-                "requested_state": "closed",
+                requested_state="closed",
-                "required_permission": "gitea.pr.close",
+                required_permission="gitea.pr.close",
-                "reasons": gate_reasons,
+            )
-                "permission_report": _permission_block_report("gitea.pr.close"),
-            }
 
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
@@ -13823,13 +13821,17 @@ def gitea_view_issue(
 
 def _permission_block_report(required_operation: str,
                              identity: str | None = None) -> dict:
-    """Structured, LLM-safe explanation of a permission denial (#142).
+    """Structured, LLM-safe explanation of a permission denial (#142, #897).
 
     Built only after a gate has already refused; it adds guidance to the
     refusal and never widens any permission, performs network I/O, or
     raises (fail-soft: degrades to a minimal fail-closed report). Names
     configured profiles only — never auth references, tokens, endpoint
     URLs, or keychain IDs.
+
+    #897: never fabricate a missing permission when the active profile
+    already allows the operation. That path is a diagnostic defect (the
+    refusal was not a permission denial), not a cue to switch profiles.
     """
     report = {
         "requested_operation": required_operation,
@@ -13841,6 +13843,7 @@ def _permission_block_report(required_operation: str,
         "matching_configured_profiles": [],
         "runtime_switching_supported": False,
         "different_mcp_namespace_required": True,
+        "diagnostic_defect": False,
         "exact_safe_next_action": (
             "Ask the operator to fix GITEA_MCP_CONFIG/GITEA_MCP_PROFILE; "
             "the active profile could not be resolved (fail closed)."),
@@ -13855,6 +13858,32 @@ def _permission_block_report(required_operation: str,
     report["active_allowed_operations"] = (
         profile.get("allowed_operations") or [])
 
+    # #897: fail closed as a diagnostic defect when the active profile
+    # already holds the operation — callers must not invent "missing".
+    try:
+        holds, _hold_reason = gitea_config.check_operation(
+            required_operation,
+            profile.get("allowed_operations") or [],
+            profile.get("forbidden_operations") or [],
+        )
+    except Exception:
+        holds = False
+    if holds:
+        report["missing_permission"] = None
+        report["required_permission"] = required_operation
+        report["diagnostic_defect"] = True
+        report["different_mcp_namespace_required"] = False
+        report["exact_safe_next_action"] = (
+            "Diagnostic defect: the active profile already allows "
+            f"{required_operation}. This is not a permission denial — "
+            "inspect blocker_kind / reasons (stale-runtime or runtime-mode). "
+            "Do not call gitea_activate_profile or switch MCP sessions."
+        )
+        report["matching_configured_profiles"] = [
+            p for p in [profile.get("profile_name")] if p
+        ]
+        return report
+
     matching = []
     try:
         config = gitea_config.load_config() or {}
@@ -13903,6 +13932,205 @@ def _permission_block_report(required_operation: str,
     return report
 
 
+def _reason_is_stale_runtime(reason: str) -> bool:
+    """True when *reason* is a master-parity / stale-daemon refusal (#897)."""
+    r = (reason or "").lower()
+    if not r:
+        return False
+    if "stale relative to live master" in r:
+        return True
+    if "server code is stale" in r:
+        return True
+    if "daemon is stale" in r:
+        return True
+    if "started at commit" in r and "workspace master is now" in r:
+        return True
+    if "mcp server started at" in r and "stale" in r:
+        return True
+    if "restart the server to load the current capability gates" in r:
+        return True
+    if "restart/reconnect before mutating" in r:
+        return True
+    return False
+
+
+def _reason_is_runtime_mode(reason: str) -> bool:
+    """True when *reason* is a stable-control / runtime-mode refusal (#897)."""
+    r = (reason or "").lower()
+    if not r:
+        return False
+    if _reason_is_stale_runtime(reason):
+        return False
+    if "runtime mode could not be assessed" in r:
+        return True
+    if "runtime mode is" in r:
+        return True
+    if "stable control runtime" in r:
+        return True
+    if "dev-test" in r and ("runtime" in r or "production" in r):
+        return True
+    if "development worktree" in r or "dev worktree" in r:
+        return True
+    if "launched from a 'branches/" in r or "launched from a \"branches/" in r:
+        return True
+    if "process-root / active-workspace alignment" in r:
+        return True
+    if "namespace" in r and "reproof" in r:
+        return True
+    return False
+
+
+def _reason_is_permission(reason: str) -> bool:
+    """True when *reason* is a genuine profile-permission denial (#897)."""
+    r = (reason or "").lower()
+    if not r:
+        return False
+    if _reason_is_stale_runtime(reason) or _reason_is_runtime_mode(reason):
+        return False
+    if "profile could not be resolved" in r:
+        return True
+    if "profile has no configured allowed operations" in r:
+        return True
+    if "profile forbids" in r:
+        return True
+    if "profile is not allowed to" in r:
+        return True
+    if "unrecognized forbidden operation" in r:
+        return True
+    return False
+
+
+def _classify_operation_gate_reasons(reasons: list[str]) -> dict:
+    """Partition gate reasons into stale / runtime-mode / permission (#897)."""
+    stale: list[str] = []
+    runtime_mode: list[str] = []
+    permission: list[str] = []
+    other: list[str] = []
+    for reason in reasons or []:
+        if _reason_is_stale_runtime(reason):
+            stale.append(reason)
+        elif _reason_is_runtime_mode(reason):
+            runtime_mode.append(reason)
+        elif _reason_is_permission(reason):
+            permission.append(reason)
+        else:
+            other.append(reason)
+    return {
+        "stale_runtime": stale,
+        "runtime_mode": runtime_mode,
+        "permission": permission,
+        "other": other,
+    }
+
+
+def _stale_runtime_reconnect_action() -> str:
+    """Sanctioned recovery for a stale daemon — reconnect only (#685/#897)."""
+    return (
+        "Reconnect the IDE/client MCP session so the server reloads at the "
+        "current master head. Do not call gitea_activate_profile or switch "
+        "MCP role sessions — profile switching does not clear a stale daemon."
+    )
+
+
+def _build_operation_gate_refusal(
+    required_operation: str,
+    reasons: list[str],
+    **extra_fields,
+) -> dict:
+    """Structured gate refusal with typed blockers (#897).
+
+    Stale-runtime and runtime-mode refusals never attach a
+    ``permission_report`` and never recommend profile switching. True
+    permission denials still get ``permission_report``. When both apply,
+    causes are reported separately under distinct fields.
+    """
+    classified = _classify_operation_gate_reasons(reasons)
+    stale = classified["stale_runtime"]
+    runtime_mode = classified["runtime_mode"]
+    permission = classified["permission"]
+    other = classified["other"]
+
+    blocked: dict = {
+        "success": False,
+        "performed": False,
+        "reasons": list(reasons),
+        "mutation_performed": False,
+        "session_context_audit": session_ctx.mutation_context_audit_fields(),
+        "gate_reason_classes": {
+            "stale_runtime": list(stale),
+            "runtime_mode": list(runtime_mode),
+            "permission": list(permission),
+            "other": list(other),
+        },
+    }
+
+    if stale:
+        parity = _current_master_parity()
+        blocked["blocker_kind"] = "runtime_reconnect_required"
+        blocked["restart_required"] = True
+        blocked["stop_required"] = True
+        blocked["startup_head"] = parity.get("startup_head")
+        blocked["current_head"] = parity.get("current_head")
+        blocked["daemon_start_head"] = (
+            parity.get("daemon_start_head") or parity.get("startup_head")
+        )
+        blocked["local_head"] = (
+            parity.get("local_head") or parity.get("current_head")
+        )
+        blocked["live_remote_head"] = parity.get("live_remote_head")
+        blocked["live_stale"] = bool(parity.get("live_stale"))
+        blocked["live_known"] = bool(parity.get("live_known"))
+        blocked["exact_safe_next_action"] = _stale_runtime_reconnect_action()
+        if permission or other:
+            blocked["permission_block_reasons"] = list(permission) + list(other)
+            blocked["stale_runtime_reasons"] = list(stale)
+        # Never attach permission_report for a staleness refusal.
+        blocked.update(extra_fields)
+        return blocked
+
+    if runtime_mode:
+        blocked["blocker_kind"] = "runtime_mode_blocked"
+        blocked["restart_required"] = False
+        blocked["stop_required"] = True
+        blocked["exact_safe_next_action"] = (
+            "Real workflow mutations run only on the promoted stable control "
+            "runtime. Promote/reload the stable runtime; do not call "
+            "gitea_activate_profile or switch MCP role sessions to clear a "
+            "runtime-mode block."
+        )
+        if permission or other:
+            blocked["permission_block_reasons"] = list(permission) + list(other)
+            blocked["runtime_mode_reasons"] = list(runtime_mode)
+        blocked.update(extra_fields)
+        return blocked
+
+    # Pure permission (or unclassified-as-permission) denial.
+    blocked["blocker_kind"] = "permission_denied"
+    blocked["permission_report"] = _permission_block_report(required_operation)
+    blocked.update(extra_fields)
+    return blocked
+
+
+def _permission_report_for_gate_reasons(
+    required_operation: str,
+    reasons: list[str] | None,
+) -> dict | None:
+    """Attach ``permission_report`` only for true permission denials (#897).
+
+    Call sites that historically always attached a permission report after
+    ``_profile_operation_gate`` should use this so stale/runtime refusals
+    do not emit a fabricated missing-permission payload.
+    """
+    if not reasons:
+        return None
+    classified = _classify_operation_gate_reasons(reasons)
+    if classified["stale_runtime"] or classified["runtime_mode"]:
+        return None
+    if not (classified["permission"] or classified["other"]):
+        return None
+    return _permission_block_report(required_operation)
+
+
 def _role_for_operation(op: str) -> str | None:
     # Normalize op first
     try:
@@ -14079,7 +14307,7 @@ def _master_parity_block(op: str) -> list[str]:
 
 
 def _profile_operation_gate(op: str) -> list[str]:
-    """Profile permission check for a single gated operation (#126, #216, #420).
+    """Profile permission check for a single gated operation (#126, #216, #420, #897).
 
     Issue discussion comments are gated separately from the gitea.pr.*
     review/merge family: listing requires ``gitea.read``, creating requires
@@ -14092,21 +14320,26 @@ def _profile_operation_gate(op: str) -> list[str]:
     capability gate that has since been merged, and when the runtime itself is
     not the promoted stable control runtime (#615) -- a dev/test or unknown
     runtime holds production credentials but has not been promoted.
+
+    #897: collect *all* independent refusal classes (stale, runtime-mode,
+    permission) rather than short-circuiting after the first. Callers that
+    only need a boolean still treat any non-empty list as blocked; typed
+    consumers (``_build_operation_gate_refusal``) can separate causes.
     """
-    stale_reasons = _master_parity_block(op)
+    reasons: list[str] = []
-    if stale_reasons:
+    reasons.extend(_master_parity_block(op))
-        return stale_reasons
+    reasons.extend(_runtime_mode_block(op))
-    runtime_reasons = _runtime_mode_block(op)
-    if runtime_reasons:
-        return runtime_reasons
     try:
         profile = get_profile()
     except Exception as exc:
-        return [f"profile could not be resolved (fail closed): {_redact(str(exc))}"]
+        reasons.append(
+            f"profile could not be resolved (fail closed): {_redact(str(exc))}"
+        )
+        return reasons
     op_ok, op_reason = gitea_config.check_operation(
         op, profile["allowed_operations"], profile["forbidden_operations"])
     if op_ok:
-        return []
+        return reasons
 
     if _try_auto_switch_for_operation(op):
         try:
@@ -14114,17 +14347,26 @@ def _profile_operation_gate(op: str) -> list[str]:
             op_ok, op_reason = gitea_config.check_operation(
                 op, profile["allowed_operations"], profile["forbidden_operations"])
             if op_ok:
-                return []
+                return reasons
         except Exception as exc:
-            return [f"profile could not be resolved (fail closed): {_redact(str(exc))}"]
+            reasons.append(
+                f"profile could not be resolved (fail closed): {_redact(str(exc))}"
+            )
+            return reasons
 
     if op_reason == "no-allowed-operations":
-        return ["profile has no configured allowed operations (fail closed)"]
+        reasons.append(
-    if op_reason == "forbidden":
+            "profile has no configured allowed operations (fail closed)"
-        return [f"profile forbids '{op}'"]
+        )
-    if op_reason == "invalid-forbidden-entry":
+    elif op_reason == "forbidden":
-        return ["profile has an unrecognized forbidden operation entry (fail closed)"]
+        reasons.append(f"profile forbids '{op}'")
-    return [f"profile is not allowed to {op}"]
+    elif op_reason == "invalid-forbidden-entry":
+        reasons.append(
+            "profile has an unrecognized forbidden operation entry (fail closed)"
+        )
+    else:
+        reasons.append(f"profile is not allowed to {op}")
+    return reasons
 
 
 def _mutation_config_authority_block(required_operation: str) -> dict | None:
@@ -14344,10 +14586,14 @@ def _session_context_mutation_block(
 
 
 def _profile_permission_block(required_operation: str, **extra_fields) -> dict | None:
-    """Structured permission denial for gated tools (#69, #142).
+    """Structured operation-gate denial for gated tools (#69, #142, #897).
 
     Returns a block dict when the active profile forbids *required_operation*,
-    or ``None`` when the gate passes. Never performs network I/O.
+    the daemon is stale, or the runtime mode is not mutation-safe — or
+    ``None`` when the gate passes. Never performs network I/O.
+
+    #897: stale-runtime and runtime-mode refusals are typed
+    (``blocker_kind``) and never carry a ``permission_report``.
     """
     req_role = "reviewer" if any(required_operation.startswith(p) for p in (
         "gitea.pr.approve", "gitea.pr.merge", "gitea.pr.request_changes", "gitea.pr.review"
@@ -14357,15 +14603,9 @@ def _profile_permission_block(required_operation: str, **extra_fields) -> dict |
 
     reasons = _profile_operation_gate(required_operation)
     if reasons:
-        blocked = {
+        return _build_operation_gate_refusal(
-            "success": False,
+            required_operation, reasons, **extra_fields
-            "performed": False,
+        )
-            "reasons": reasons,
-            "permission_report": _permission_block_report(required_operation),
-            "session_context_audit": session_ctx.mutation_context_audit_fields(),
-        }
-        blocked.update(extra_fields)
-        return blocked
 
     auth_block = _mutation_config_authority_block(required_operation)
     if auth_block is not None:
@@ -14494,20 +14734,14 @@ def gitea_acquire_reviewer_pr_lease(
     """Acquire a per-PR reviewer lease before review/merge mutations (#407)."""
     read_block = _profile_operation_gate("gitea.read")
     if read_block:
-        return {
+        return _build_operation_gate_refusal(
-            "success": False,
+            "gitea.read", read_block, acquired=False
-            "acquired": False,
+        )
-            "reasons": read_block,
-            "permission_report": _permission_block_report("gitea.read"),
-        }
     comment_block = _profile_operation_gate("gitea.pr.comment")
     if comment_block:
-        return {
+        return _build_operation_gate_refusal(
-            "success": False,
+            "gitea.pr.comment", comment_block, acquired=False
-            "acquired": False,
+        )
-            "reasons": comment_block,
-            "permission_report": _permission_block_report("gitea.pr.comment"),
-        }
 
     # task=acquire_reviewer_pr_lease so verify_preflight_purity runs shared #604
     # anti-stomp for the declared lease-acquire mutation inventory entry.
@@ -14623,20 +14857,14 @@ def gitea_acquire_merger_pr_lease(
     """
     read_block = _profile_operation_gate("gitea.read")
     if read_block:
-        return {
+        return _build_operation_gate_refusal(
-            "success": False,
+            "gitea.read", read_block, acquired=False
-            "acquired": False,
+        )
-            "reasons": read_block,
-            "permission_report": _permission_block_report("gitea.read"),
-        }
     comment_block = _profile_operation_gate("gitea.pr.comment")
     if comment_block:
-        return {
+        return _build_operation_gate_refusal(
-            "success": False,
+            "gitea.pr.comment", comment_block, acquired=False
-            "acquired": False,
+        )
-            "reasons": comment_block,
-            "permission_report": _permission_block_report("gitea.pr.comment"),
-        }
     merge_block = _profile_operation_gate("gitea.pr.merge")
     if merge_block:
         return {
@@ -19375,14 +19603,12 @@ def gitea_update_pr_branch_by_merge(
     # Permission: author branch push / PR mutation surface.
     push_block = _profile_operation_gate("gitea.branch.push")
     if push_block:
-        return {
+        return _build_operation_gate_refusal(
-            "success": False,
+            "gitea.branch.push",
-            "performed": False,
+            push_block,
-            "mutation_allowed": False,
+            mutation_allowed=False,
-            "reasons": push_block,
+            role_kind=role,
-            "permission_report": _permission_block_report("gitea.branch.push"),
+        )
-            "role_kind": role,
-        }
 
     if role != "author":
         pre = pr_sync_status.assess_update_pr_branch_preflight(

tests/test_issue_897_permission_stale_runtime_classification.py

@@ -0,0 +1,453 @@
+"""#897: stale-runtime / runtime-mode refusals must not look like permission denials.
+
+Acceptance criteria (issue #897):
+
+* Stale-runtime and runtime-mode refusals are typed distinctly from
+  profile-permission refusals (distinct ``blocker_kind``).
+* A refusal caused by staleness or runtime mode never emits a
+  ``permission_report`` and never names a permission the active profile holds.
+* ``_permission_block_report`` verifies the active profile actually lacks the
+  operation before reporting it missing.
+* A stale-runtime refusal reports reconnect-only recovery and never recommends
+  ``gitea_activate_profile`` or an MCP session switch.
+* The blocker payload states the observed heads (parity fields).
+* Matrix across author / reviewer / merger / reconciler profiles.
+* Regression: ``gitea_create_issue`` on a stale daemon under ``prgs-author``
+  never returns ``missing_permission: gitea.issue.create``.
+"""
+from __future__ import annotations
+
+import os
+import sys
+import unittest
+from unittest.mock import patch
+
+sys.path.insert(0, str(__import__("pathlib").Path(__file__).resolve().parent.parent))
+
+import gitea_config  # noqa: E402
+import gitea_mcp_server as mcp_server  # noqa: E402
+
+SHA_START = "7af40fb5ff7debd5e9165fe97d9c7c279358e175"
+SHA_LIVE = "2f4dec832327513118f2fe92b74da25d124a01cb"
+
+ROLE_MATRIX = (
+    (
+        "prgs-author",
+        "author",
+        "gitea.issue.create",
+        [
+            "gitea.read",
+            "gitea.issue.create",
+            "gitea.issue.comment",
+            "gitea.issue.close",
+            "gitea.branch.create",
+            "gitea.branch.push",
+            "gitea.pr.create",
+            "gitea.pr.comment",
+            "gitea.repo.commit",
+        ],
+        ["gitea.pr.approve", "gitea.pr.merge", "gitea.pr.request_changes"],
+        "gitea.pr.merge",  # forbidden op for pure-permission case
+    ),
+    (
+        "prgs-reviewer",
+        "reviewer",
+        "gitea.pr.review",
+        [
+            "gitea.read",
+            "gitea.pr.review",
+            "gitea.pr.approve",
+            "gitea.pr.request_changes",
+            "gitea.pr.comment",
+            "gitea.issue.comment",
+        ],
+        ["gitea.branch.push", "gitea.pr.create"],
+        "gitea.branch.push",
+    ),
+    (
+        "prgs-merger",
+        "merger",
+        "gitea.pr.merge",
+        [
+            "gitea.read",
+            "gitea.pr.merge",
+            "gitea.pr.comment",
+            "gitea.issue.comment",
+        ],
+        ["gitea.pr.approve", "gitea.branch.push", "gitea.pr.create"],
+        "gitea.branch.push",
+    ),
+    (
+        "prgs-reconciler",
+        "reconciler",
+        "gitea.branch.delete",
+        [
+            "gitea.read",
+            "gitea.branch.delete",
+            "gitea.pr.comment",
+            "gitea.issue.comment",
+            "gitea.pr.close",
+            "gitea.issue.close",
+        ],
+        ["gitea.pr.approve", "gitea.pr.merge"],
+        "gitea.pr.merge",
+    ),
+)
+
+
+def _profile(name: str, role: str, allowed: list[str], forbidden: list[str]) -> dict:
+    return {
+        "profile_name": name,
+        "role": role,
+        "role_kind": role,
+        "allowed_operations": list(allowed),
+        "forbidden_operations": list(forbidden),
+        "identity": "test-user",
+    }
+
+
+def _config(profiles: dict) -> dict:
+    return {
+        "version": 2,
+        "profiles": {
+            name: {
+                "role": p["role"],
+                "allowed_operations": p["allowed_operations"],
+                "forbidden_operations": p["forbidden_operations"],
+            }
+            for name, p in profiles.items()
+        },
+        "rules": {"allow_runtime_switching": True},
+    }
+
+
+class Issue897Helpers(unittest.TestCase):
+    def test_classify_stale_reason_strings(self):
+        stale = (
+            f"live remote master is {SHA_LIVE[:12]} but the MCP server started "
+            f"at {SHA_START[:12]}; the daemon is stale relative to live master "
+            "-- restart/reconnect before mutating"
+        )
+        classified = mcp_server._classify_operation_gate_reasons([stale])
+        self.assertEqual(classified["stale_runtime"], [stale])
+        self.assertEqual(classified["permission"], [])
+        self.assertEqual(classified["runtime_mode"], [])
+
+    def test_classify_permission_reason(self):
+        reason = "profile is not allowed to gitea.pr.merge"
+        classified = mcp_server._classify_operation_gate_reasons([reason])
+        self.assertEqual(classified["permission"], [reason])
+        self.assertEqual(classified["stale_runtime"], [])
+
+    def test_classify_runtime_mode_reason(self):
+        reason = (
+            "runtime mode is 'dev-test' and the mutation targets the "
+            "production repository; dev/test runtimes must not mutate real "
+            "issues or PRs (ADR: stable control runtime vs dev runtime)"
+        )
+        classified = mcp_server._classify_operation_gate_reasons([reason])
+        self.assertEqual(classified["runtime_mode"], [reason])
+        self.assertEqual(classified["stale_runtime"], [])
+
+
+class Issue897PermissionBlockReport(unittest.TestCase):
+    def test_holds_op_is_diagnostic_defect_not_missing_permission(self):
+        profile = _profile(
+            "prgs-author",
+            "author",
+            ["gitea.read", "gitea.issue.create", "gitea.issue.comment"],
+            [],
+        )
+        with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+            mcp_server.gitea_config, "load_config", return_value=_config({"prgs-author": profile})
+        ), patch.object(
+            mcp_server.gitea_config, "is_runtime_switching_enabled", return_value=True
+        ):
+            report = mcp_server._permission_block_report("gitea.issue.create")
+        self.assertTrue(report.get("diagnostic_defect"), report)
+        self.assertIsNone(report.get("missing_permission"), report)
+        action = (report.get("exact_safe_next_action") or "").lower()
+        # Must not *recommend* profile switching; mentioning the forbidden
+        # action in a "do not call" instruction is fine.
+        self.assertNotIn("call gitea_activate_profile with", action)
+        self.assertNotIn("switch to the author mcp session", action)
+        self.assertNotIn("switch to the reviewer mcp session", action)
+        self.assertIn("diagnostic defect", action)
+
+    def test_true_missing_permission_still_reports(self):
+        profile = _profile(
+            "prgs-author",
+            "author",
+            ["gitea.read", "gitea.issue.create"],
+            ["gitea.pr.merge"],
+        )
+        reviewer = _profile(
+            "prgs-reviewer",
+            "reviewer",
+            ["gitea.read", "gitea.pr.merge", "gitea.pr.approve"],
+            [],
+        )
+        with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+            mcp_server.gitea_config,
+            "load_config",
+            return_value=_config({"prgs-author": profile, "prgs-reviewer": reviewer}),
+        ), patch.object(
+            mcp_server.gitea_config, "is_runtime_switching_enabled", return_value=True
+        ):
+            report = mcp_server._permission_block_report("gitea.pr.merge")
+        self.assertFalse(report.get("diagnostic_defect"), report)
+        self.assertEqual(report.get("missing_permission"), "gitea.pr.merge")
+        self.assertIn("prgs-reviewer", report.get("matching_configured_profiles") or [])
+
+
+class Issue897GateRefusalMatrix(unittest.TestCase):
+    def _stale_parity(self) -> dict:
+        return {
+            "in_parity": True,
+            "stale": False,
+            "restart_required": True,
+            "determinable": True,
+            "startup_head": SHA_START,
+            "current_head": SHA_START,
+            "daemon_start_head": SHA_START,
+            "local_head": SHA_START,
+            "live_remote_head": SHA_LIVE,
+            "live_known": True,
+            "live_stale": True,
+            "mutation_safe": False,
+            "reasons": [
+                f"live remote master is {SHA_LIVE[:12]} but the MCP server "
+                f"started at {SHA_START[:12]}; the daemon is stale relative "
+                "to live master -- restart/reconnect before mutating"
+            ],
+        }
+
+    def test_stale_plus_permitted_op_all_roles(self):
+        for name, role, permitted_op, allowed, forbidden, _forbidden_op in ROLE_MATRIX:
+            with self.subTest(profile=name, op=permitted_op):
+                profile = _profile(name, role, allowed, forbidden)
+                parity = self._stale_parity()
+                with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+                    mcp_server, "_current_master_parity", return_value=parity
+                ), patch.object(
+                    mcp_server, "_master_parity_block", return_value=list(parity["reasons"])
+                ), patch.object(
+                    mcp_server, "_runtime_mode_block", return_value=[]
+                ), patch.object(
+                    mcp_server, "_ensure_matching_profile", return_value=None
+                ), patch.object(
+                    mcp_server.session_ctx,
+                    "mutation_context_audit_fields",
+                    return_value={"session_profile": name},
+                ):
+                    blocked = mcp_server._profile_permission_block(permitted_op)
+                self.assertIsNotNone(blocked, name)
+                assert blocked is not None
+                self.assertEqual(
+                    blocked.get("blocker_kind"),
+                    "runtime_reconnect_required",
+                    blocked,
+                )
+                self.assertNotIn("permission_report", blocked, blocked)
+                self.assertTrue(blocked.get("restart_required"), blocked)
+                self.assertEqual(blocked.get("startup_head"), SHA_START, blocked)
+                self.assertEqual(blocked.get("live_remote_head"), SHA_LIVE, blocked)
+                action = (blocked.get("exact_safe_next_action") or "").lower()
+                self.assertIn("reconnect", action)
+                self.assertNotIn("call gitea_activate_profile with", action)
+                self.assertNotIn("switch to the author mcp session", action)
+                self.assertNotIn("switch to the reviewer mcp session", action)
+
+    def test_fresh_plus_forbidden_op_all_roles(self):
+        for name, role, _permitted, allowed, forbidden, forbidden_op in ROLE_MATRIX:
+            with self.subTest(profile=name, op=forbidden_op):
+                profile = _profile(name, role, allowed, forbidden)
+                with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+                    mcp_server, "_master_parity_block", return_value=[]
+                ), patch.object(
+                    mcp_server, "_runtime_mode_block", return_value=[]
+                ), patch.object(
+                    mcp_server, "_ensure_matching_profile", return_value=None
+                ), patch.object(
+                    mcp_server.session_ctx,
+                    "mutation_context_audit_fields",
+                    return_value={"session_profile": name},
+                ), patch.object(
+                    mcp_server.gitea_config,
+                    "load_config",
+                    return_value=_config({name: profile}),
+                ), patch.object(
+                    mcp_server.gitea_config, "is_runtime_switching_enabled", return_value=False
+                ):
+                    blocked = mcp_server._profile_permission_block(forbidden_op)
+                self.assertIsNotNone(blocked, name)
+                assert blocked is not None
+                self.assertEqual(blocked.get("blocker_kind"), "permission_denied", blocked)
+                self.assertIn("permission_report", blocked, blocked)
+                report = blocked["permission_report"]
+                self.assertEqual(report.get("missing_permission"), forbidden_op, report)
+                self.assertFalse(report.get("diagnostic_defect"), report)
+                # No runtime reconnect fields for pure permission denial
+                self.assertNotEqual(
+                    blocked.get("blocker_kind"), "runtime_reconnect_required"
+                )
+
+    def test_stale_plus_forbidden_op_both_causes_separated(self):
+        for name, role, _permitted, allowed, forbidden, forbidden_op in ROLE_MATRIX:
+            with self.subTest(profile=name, op=forbidden_op):
+                profile = _profile(name, role, allowed, forbidden)
+                parity = self._stale_parity()
+                stale_reason = parity["reasons"][0]
+                with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+                    mcp_server, "_current_master_parity", return_value=parity
+                ), patch.object(
+                    mcp_server, "_master_parity_block", return_value=[stale_reason]
+                ), patch.object(
+                    mcp_server, "_runtime_mode_block", return_value=[]
+                ), patch.object(
+                    mcp_server, "_ensure_matching_profile", return_value=None
+                ), patch.object(
+                    mcp_server.session_ctx,
+                    "mutation_context_audit_fields",
+                    return_value={"session_profile": name},
+                ):
+                    # Gate collects both classes; force permission reason too.
+                    with patch.object(
+                        mcp_server,
+                        "_profile_operation_gate",
+                        return_value=[
+                            stale_reason,
+                            f"profile is not allowed to {forbidden_op}",
+                        ],
+                    ):
+                        blocked = mcp_server._profile_permission_block(forbidden_op)
+                self.assertIsNotNone(blocked)
+                assert blocked is not None
+                self.assertEqual(
+                    blocked.get("blocker_kind"), "runtime_reconnect_required", blocked
+                )
+                self.assertNotIn("permission_report", blocked, blocked)
+                self.assertIn("permission_block_reasons", blocked, blocked)
+                self.assertIn("stale_runtime_reasons", blocked, blocked)
+                classes = blocked.get("gate_reason_classes") or {}
+                self.assertTrue(classes.get("stale_runtime"), classes)
+                self.assertTrue(classes.get("permission"), classes)
+
+    def test_runtime_mode_block_no_permission_report(self):
+        profile = _profile(
+            "prgs-author",
+            "author",
+            ["gitea.read", "gitea.issue.create"],
+            [],
+        )
+        runtime_reason = (
+            "runtime mode is 'dev-test' and the mutation targets the "
+            "production repository; dev/test runtimes must not mutate real "
+            "issues or PRs (ADR: stable control runtime vs dev runtime)"
+        )
+        with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+            mcp_server, "_master_parity_block", return_value=[]
+        ), patch.object(
+            mcp_server, "_runtime_mode_block", return_value=[runtime_reason]
+        ), patch.object(
+            mcp_server, "_ensure_matching_profile", return_value=None
+        ), patch.object(
+            mcp_server.session_ctx,
+            "mutation_context_audit_fields",
+            return_value={"session_profile": "prgs-author"},
+        ):
+            blocked = mcp_server._profile_permission_block("gitea.issue.create")
+        self.assertIsNotNone(blocked)
+        assert blocked is not None
+        self.assertEqual(blocked.get("blocker_kind"), "runtime_mode_blocked", blocked)
+        self.assertNotIn("permission_report", blocked, blocked)
+        action = (blocked.get("exact_safe_next_action") or "").lower()
+        self.assertNotIn("call gitea_activate_profile with", action)
+        self.assertIn("stable control runtime", action)
+
+
+class Issue897CreateIssueRegression(unittest.TestCase):
+    def test_create_issue_stale_daemon_never_missing_issue_create(self):
+        """Regression AC: stale prgs-author create_issue must not claim missing create."""
+        profile = _profile(
+            "prgs-author",
+            "author",
+            [
+                "gitea.read",
+                "gitea.issue.create",
+                "gitea.issue.comment",
+                "gitea.branch.create",
+                "gitea.branch.push",
+                "gitea.pr.create",
+                "gitea.pr.comment",
+                "gitea.repo.commit",
+            ],
+            [],
+        )
+        stale_reason = (
+            f"live remote master is {SHA_LIVE[:12]} but the MCP server started "
+            f"at {SHA_START[:12]}; the daemon is stale relative to live master "
+            "-- restart/reconnect before mutating"
+        )
+        parity = {
+            "in_parity": True,
+            "stale": False,
+            "restart_required": True,
+            "determinable": True,
+            "startup_head": SHA_START,
+            "current_head": SHA_START,
+            "daemon_start_head": SHA_START,
+            "local_head": SHA_START,
+            "live_remote_head": SHA_LIVE,
+            "live_known": True,
+            "live_stale": True,
+            "mutation_safe": False,
+            "reasons": [stale_reason],
+        }
+
+        with patch.object(mcp_server, "get_profile", return_value=profile), patch.object(
+            mcp_server, "_current_master_parity", return_value=parity
+        ), patch.object(
+            mcp_server, "_master_parity_block", return_value=[stale_reason]
+        ), patch.object(
+            mcp_server, "_runtime_mode_block", return_value=[]
+        ), patch.object(
+            mcp_server, "_ensure_matching_profile", return_value=None
+        ), patch.object(
+            mcp_server.session_ctx,
+            "mutation_context_audit_fields",
+            return_value={"session_profile": "prgs-author"},
+        ), patch.object(
+            mcp_server, "_mutation_config_authority_block", return_value=None
+        ), patch.object(
+            mcp_server, "_session_context_mutation_block", return_value=None
+        ):
+            blocked = mcp_server._profile_permission_block(
+                "gitea.issue.create", remote="prgs"
+            )
+
+        self.assertIsNotNone(blocked)
+        assert blocked is not None
+        self.assertEqual(blocked.get("blocker_kind"), "runtime_reconnect_required")
+        self.assertNotIn("permission_report", blocked)
+        # Even if a caller still built a raw report, holds-check must not claim missing.
+        with patch.object(mcp_server, "get_profile", return_value=profile):
+            raw = mcp_server._permission_block_report("gitea.issue.create")
+        self.assertIsNone(raw.get("missing_permission"), raw)
+        self.assertNotEqual(raw.get("missing_permission"), "gitea.issue.create")
+
+    def test_permission_report_for_gate_reasons_skips_stale(self):
+        stale = (
+            f"live remote master is {SHA_LIVE[:12]} but the MCP server started "
+            f"at {SHA_START[:12]}; the daemon is stale relative to live master "
+            "-- restart/reconnect before mutating"
+        )
+        self.assertIsNone(
+            mcp_server._permission_report_for_gate_reasons(
+                "gitea.issue.comment", [stale]
+            )
+        )
+
+
+if __name__ == "__main__":
+    unittest.main()

tests/test_webui_gitea_linkage.py

@@ -0,0 +1,511 @@
+"""Tests for the Gitea issue↔PR linkage console (#645, Phase 3).
+
+Covers the acceptance criteria of the issue:
+
+* AC1 — issue↔PR linkage is visible for the selected project/repo, in both
+  directions, with the evidence that produced each edge.
+* AC2 — the latest canonical handoff (CTH) is summarized for a focused thread.
+* AC3 — an external Gitea link appears only under the admin reveal opt-in.
+* AC4 — every case is driven by mocked Gitea payloads; no network.
+
+Plus the invariants this console must not violate: a partial or failed read is
+never rendered as "no link exists", an unfetched thread is never rendered as
+"no handoff", redaction happens before display, and the surface stays read-only.
+"""
+
+from __future__ import annotations
+
+import json
+import os
+import sys
+import unittest
+from pathlib import Path
+from unittest import mock
+
+sys.path.insert(0, str(Path(__file__).resolve().parent.parent))
+
+from tests.webui_testclient import TestClient
+
+from canonical_thread_handoff import format_cth_body
+from webui.app import create_app
+from webui.linkage_loader import (
+    EVIDENCE_BRANCH,
+    EVIDENCE_CLOSES,
+    EVIDENCE_REFERENCE,
+    HANDOFF_LOADED,
+    HANDOFF_NOT_LOADED,
+    HANDOFF_UNAVAILABLE,
+    LinkageSnapshot,
+    load_linkage_snapshot,
+    resolve_linkage,
+    resolve_pr_links,
+    snapshot_to_dict,
+    summarize_handoff,
+)
+from webui.linkage_views import render_linkage_page
+from webui.nav import nav_hrefs
+from webui.queue_loader import PaginationMeta
+
+
+def _pagination(*, complete: bool = True, count: int = 0) -> PaginationMeta:
+    return PaginationMeta(
+        page=1,
+        per_page=50,
+        returned_count=count,
+        has_more=not complete,
+        is_final_page=complete,
+        inventory_complete=complete,
+        pages_fetched=1,
+    )
+
+
+def _pr(
+    number: int,
+    *,
+    title: str = "",
+    body: str = "",
+    head: str = "",
+    state: str = "open",
+    labels: tuple[str, ...] = (),
+) -> dict:
+    return {
+        "number": number,
+        "title": title or f"pr {number}",
+        "body": body,
+        "state": state,
+        "head": {"ref": head},
+        "labels": [{"name": name} for name in labels],
+    }
+
+
+def _issue(
+    number: int,
+    *,
+    title: str = "",
+    state: str = "open",
+    labels: tuple[str, ...] = (),
+) -> dict:
+    return {
+        "number": number,
+        "title": title or f"issue {number}",
+        "state": state,
+        "labels": [{"name": name} for name in labels],
+    }
+
+
+def _fetcher(items: list[dict], *, complete: bool = True):
+    def _fetch(*_args, **_kwargs):
+        return items, _pagination(complete=complete, count=len(items))
+
+    return _fetch
+
+
+def _load(
+    issues: list[dict],
+    prs: list[dict],
+    *,
+    complete: bool = True,
+    **kwargs,
+) -> LinkageSnapshot:
+    return load_linkage_snapshot(
+        fetch_prs=_fetcher(prs, complete=complete),
+        fetch_issues=_fetcher(issues, complete=complete),
+        **kwargs,
+    )
+
+
+def _cth(comment_id: int, *, created_at: str, status: str, next_owner: str) -> dict:
+    return {
+        "id": comment_id,
+        "created_at": created_at,
+        "user": {"login": "jcwalker3"},
+        "body": format_cth_body(
+            cth_type="Author Handoff",
+            status=status,
+            next_owner=next_owner,
+            current_blocker="none",
+            decision="implemented",
+            proof="full suite green",
+            next_action="review PR",
+            ready_to_paste_prompt="Review PR #902 now.",
+        ),
+    }
+
+
+class TestLinkageEvidence(unittest.TestCase):
+    """AC1 — every edge records how it was found, and keeps all candidates."""
+
+    def test_closes_keyword_in_body_is_strongest_evidence(self):
+        links = resolve_pr_links(_pr(902, body="Closes #643"))
+        self.assertEqual([link.issue_number for link in links], [643])
+        self.assertEqual(links[0].evidence, (EVIDENCE_CLOSES,))
+        self.assertTrue(links[0].closes)
+
+    def test_closes_keyword_in_title_counts(self):
+        links = resolve_pr_links(_pr(902, title="feat(webui): preview (Closes #643)"))
+        self.assertEqual(links[0].evidence, (EVIDENCE_CLOSES,))
+
+    def test_canonical_branch_marker_links_without_a_keyword(self):
+        links = resolve_pr_links(_pr(902, head="feat/issue-643-request-preview"))
+        self.assertEqual([link.issue_number for link in links], [643])
+        self.assertEqual(links[0].evidence, (EVIDENCE_BRANCH,))
+        self.assertFalse(links[0].closes)
+
+    def test_non_canonical_branch_is_not_treated_as_a_marker(self):
+        self.assertEqual(resolve_pr_links(_pr(902, head="issue-643-preview")), ())
+
+    def test_bare_mention_is_recorded_as_the_weakest_evidence(self):
+        links = resolve_pr_links(_pr(902, body="context in #643"))
+        self.assertEqual(links[0].evidence, (EVIDENCE_REFERENCE,))
+        self.assertFalse(links[0].closes)
+
+    def test_several_evidence_kinds_merge_onto_one_edge(self):
+        links = resolve_pr_links(
+            _pr(902, body="Closes #643 — see #643", head="feat/issue-643-preview")
+        )
+        self.assertEqual(len(links), 1)
+        self.assertEqual(
+            links[0].evidence,
+            (EVIDENCE_CLOSES, EVIDENCE_BRANCH, EVIDENCE_REFERENCE),
+        )
+
+    def test_stronger_evidence_sorts_first(self):
+        links = resolve_pr_links(_pr(902, body="Closes #643, related #700"))
+        self.assertEqual([link.issue_number for link in links], [643, 700])
+
+    def test_self_reference_is_not_linkage(self):
+        links = resolve_pr_links(_pr(902, body="supersedes #902"))
+        self.assertEqual(links, ())
+
+    def test_every_candidate_is_kept_never_collapsed_to_a_guess(self):
+        links = resolve_pr_links(_pr(902, body="Closes #643\nCloses #644"))
+        self.assertEqual([link.issue_number for link in links], [643, 644])
+
+
+class TestLinkageIndex(unittest.TestCase):
+    def test_issue_direction_ignores_mention_only_edges(self):
+        index = resolve_linkage([_pr(902, body="context in #643")])
+        self.assertIsNone(index.issue_prs.get(643))
+        self.assertEqual(index.pr_links[902][0].evidence, (EVIDENCE_REFERENCE,))
+
+    def test_contested_issue_is_reported_when_two_prs_claim_it(self):
+        index = resolve_linkage(
+            [_pr(902, body="Closes #643"), _pr(903, head="feat/issue-643-again")]
+        )
+        self.assertEqual(index.contested_issues(), (643,))
+        self.assertEqual(index.issue_prs[643], (902, 903))
+
+    def test_single_claim_is_not_contested(self):
+        index = resolve_linkage([_pr(902, body="Closes #643")])
+        self.assertEqual(index.contested_issues(), ())
+
+    def test_ambiguous_when_two_issues_tie_at_the_strongest_evidence(self):
+        index = resolve_linkage([_pr(902, body="Closes #643\nCloses #644")])
+        self.assertTrue(index.ambiguous(902))
+
+    def test_weaker_candidate_alongside_a_stronger_one_is_not_ambiguous(self):
+        index = resolve_linkage([_pr(902, body="Closes #643, see #700")])
+        self.assertFalse(index.ambiguous(902))
+        self.assertEqual(index.primary_issue(902).issue_number, 643)
+
+    def test_malformed_pr_row_is_skipped_not_raised_on(self):
+        index = resolve_linkage([{"title": "no number"}, _pr(902, body="Closes #643")])
+        self.assertEqual(sorted(index.pr_links), [902])
+
+
+class TestLinkageSnapshot(unittest.TestCase):
+    """AC1 — linkage is visible per project/repo, in both directions."""
+
+    def test_both_directions_are_populated(self):
+        snapshot = _load([_issue(643)], [_pr(902, body="Closes #643")])
+        self.assertTrue(snapshot.ok)
+        self.assertEqual([node.number for node in snapshot.issues], [643])
+        self.assertEqual(snapshot.issues[0].linked_prs, (902,))
+        self.assertEqual(snapshot.prs[0].links[0].issue_number, 643)
+
+    def test_repo_scope_comes_from_the_registry_project(self):
+        snapshot = _load([], [])
+        self.assertIn("/", snapshot.repo_label)
+        self.assertTrue(snapshot.project_id)
+
+    def test_unknown_project_fails_closed_with_a_reason(self):
+        snapshot = _load([_issue(643)], [], project_id="no-such-project")
+        self.assertFalse(snapshot.ok)
+        self.assertIn("not found in registry", snapshot.fetch_error)
+        self.assertEqual(snapshot.issues, ())
+
+    def test_orphan_pr_is_identifiable(self):
+        snapshot = _load([], [_pr(902), _pr(903, body="Closes #643")])
+        self.assertEqual([node.number for node in snapshot.orphan_prs], [902])
+
+    def test_state_scope_defaults_to_open_and_is_reported(self):
+        self.assertEqual(_load([], []).state_scope, "open")
+        self.assertEqual(_load([], [], state="all").state_scope, "all")
+
+    def test_unsupported_state_falls_back_to_open(self):
+        self.assertEqual(_load([], [], state="../etc").state_scope, "open")
+
+    def test_state_is_passed_through_to_the_fetchers(self):
+        seen: list[str] = []
+
+        def _fetch(*_args, **kwargs):
+            seen.append(kwargs.get("state", ""))
+            return [], _pagination()
+
+        load_linkage_snapshot(state="all", fetch_prs=_fetch, fetch_issues=_fetch)
+        self.assertEqual(seen, ["all", "all"])
+
+
+class TestPartialInventoryIsNotAnAbsenceClaim(unittest.TestCase):
+    """An empty edge list from a partial read must never read as 'no link'."""
+
+    def test_incomplete_pagination_marks_links_non_authoritative(self):
+        snapshot = _load([_issue(643)], [], complete=False)
+        self.assertFalse(snapshot.inventory_complete)
+        self.assertFalse(snapshot.issues[0].links_authoritative)
+
+    def test_complete_pagination_marks_links_authoritative(self):
+        snapshot = _load([_issue(643)], [], complete=True)
+        self.assertTrue(snapshot.inventory_complete)
+        self.assertTrue(snapshot.issues[0].links_authoritative)
+
+    def test_partial_window_renders_a_qualified_empty_cell(self):
+        html = render_linkage_page(_load([_issue(643)], [], complete=False))
+        self.assertIn("none found (partial inventory)", html)
+
+    def test_complete_window_renders_a_plain_none(self):
+        html = render_linkage_page(_load([_issue(643)], [], complete=True))
+        self.assertNotIn("partial inventory", html)
+        self.assertIn(">none<", html)
+
+    def test_missing_credentials_fail_closed_without_a_table(self):
+        with mock.patch(
+            "webui.linkage_loader._offline_test_mode", return_value=False
+        ), mock.patch("webui.linkage_loader.get_auth_header", return_value=""):
+            snapshot = load_linkage_snapshot()
+        self.assertFalse(snapshot.ok)
+        self.assertIn("credentials unavailable", snapshot.fetch_error)
+        html = render_linkage_page(snapshot)
+        self.assertIn("Linkage unavailable", html)
+        self.assertNotIn("Issues → pull requests", html)
+
+    def test_fetch_failure_is_reported_not_raised(self):
+        def _boom(*_args, **_kwargs):
+            raise RuntimeError("gitea 502")
+
+        snapshot = load_linkage_snapshot(fetch_prs=_boom, fetch_issues=_boom)
+        self.assertFalse(snapshot.ok)
+        self.assertIn("Gitea fetch failed", snapshot.fetch_error)
+
+
+class TestHandoffSummary(unittest.TestCase):
+    """AC2 — the latest canonical handoff is summarized for a focused thread."""
+
+    def test_latest_cth_wins(self):
+        summary = summarize_handoff([
+            _cth(1, created_at="2026-07-24T10:00:00Z", status="in progress",
+                 next_owner="author"),
+            _cth(2, created_at="2026-07-25T10:00:00Z", status="PR-open",
+                 next_owner="reviewer"),
+        ])
+        self.assertEqual(summary.comment_id, 2)
+        self.assertEqual(summary.status, "PR-open")
+        self.assertEqual(summary.next_owner, "reviewer")
+        self.assertTrue(summary.cth_type_known)
+
+    def test_thread_without_a_cth_summarizes_to_none(self):
+        self.assertIsNone(summarize_handoff([{"id": 1, "body": "ordinary comment"}]))
+
+    def test_unknown_heading_is_reported_not_republished(self):
+        summary = summarize_handoff([
+            {
+                "id": 5,
+                "created_at": "2026-07-25T10:00:00Z",
+                "user": {"login": "someone"},
+                "body": "<!-- cth:v1 -->\n## CTH: Totally Made Up\n\nStatus: odd\n",
+            }
+        ])
+        self.assertFalse(summary.cth_type_known)
+        self.assertEqual(summary.cth_type, "unrecognized")
+        self.assertNotIn("Totally Made Up", json.dumps(summary.to_dict()))
+
+    def test_focused_pr_loads_its_handoff(self):
+        snapshot = _load(
+            [_issue(643)],
+            [_pr(902, body="Closes #643")],
+            pr=902,
+            comment_source=lambda kind, number: [
+                _cth(2, created_at="2026-07-25T10:00:00Z", status="PR-open",
+                     next_owner="reviewer")
+            ],
+        )
+        self.assertEqual(snapshot.handoff_status.state, HANDOFF_LOADED)
+        self.assertEqual(snapshot.focus, ("pr", 902))
+        self.assertEqual(snapshot.prs[0].handoff.status, "PR-open")
+
+    def test_unfocused_rows_report_not_loaded_never_none(self):
+        snapshot = _load(
+            [_issue(643)],
+            [_pr(902, body="Closes #643"), _pr(903)],
+            pr=902,
+            comment_source=lambda kind, number: [],
+        )
+        other = next(node for node in snapshot.prs if node.number == 903)
+        self.assertIsNone(other.handoff)
+        self.assertEqual(other.handoff_status.state, HANDOFF_NOT_LOADED)
+        self.assertIn("not loaded", render_linkage_page(snapshot))
+
+    def test_no_focus_means_no_thread_is_claimed_handoff_free(self):
+        snapshot = _load([_issue(643)], [])
+        self.assertEqual(snapshot.handoff_status.state, HANDOFF_NOT_LOADED)
+        self.assertIn("thread-scoped", snapshot.handoff_status.reason)
+
+    def test_comment_source_failure_degrades_only_the_handoff(self):
+        def _boom(_kind, _number):
+            raise RuntimeError("comments 500")
+
+        snapshot = _load(
+            [_issue(643)], [_pr(902, body="Closes #643")], pr=902, comment_source=_boom
+        )
+        self.assertTrue(snapshot.ok)
+        self.assertEqual(snapshot.handoff_status.state, HANDOFF_UNAVAILABLE)
+        self.assertEqual(snapshot.issues[0].linked_prs, (902,))
+        self.assertIn("unavailable", render_linkage_page(snapshot))
+
+    def test_loaded_thread_with_no_cth_says_so_explicitly(self):
+        snapshot = _load(
+            [_issue(643)],
+            [_pr(902, body="Closes #643")],
+            pr=902,
+            comment_source=lambda kind, number: [{"id": 1, "body": "hi"}],
+        )
+        self.assertIn(
+            "no Canonical Thread Handoff comment found", render_linkage_page(snapshot)
+        )
+
+
+class TestDeepLinks(unittest.TestCase):
+    """AC3 — an external Gitea link is emitted only when permitted."""
+
+    def test_deep_links_are_withheld_by_default(self):
+        with mock.patch.dict(os.environ, {"GITEA_MCP_REVEAL_ENDPOINTS": ""}):
+            snapshot = _load([_issue(643)], [])
+            html = render_linkage_page(snapshot)
+        self.assertFalse(snapshot.deep_links_enabled)
+        self.assertIsNone(snapshot.issues[0].deep_link)
+        self.assertIn("Gitea deep links are withheld", html)
+
+    def test_reveal_opt_in_emits_the_link(self):
+        with mock.patch.dict(os.environ, {"GITEA_MCP_REVEAL_ENDPOINTS": "1"}):
+            snapshot = _load([_issue(643)], [_pr(902, body="Closes #643")])
+            html = render_linkage_page(snapshot)
+        self.assertTrue(snapshot.deep_links_enabled)
+        self.assertIn("/issues/643", snapshot.issues[0].deep_link)
+        self.assertIn("/pulls/902", snapshot.prs[0].deep_link)
+        self.assertIn(f'href="{snapshot.issues[0].deep_link}"', html)
+
+
+class TestRedactionBoundary(unittest.TestCase):
+    def test_secret_shaped_title_is_redacted_before_display(self):
+        snapshot = _load(
+            [_issue(643, title="token=ghp_thisisnotarealsecretvalue0001")], []
+        )
+        payload = json.dumps(snapshot_to_dict(snapshot))
+        self.assertNotIn("ghp_thisisnotarealsecretvalue0001", payload)
+        self.assertNotIn(
+            "ghp_thisisnotarealsecretvalue0001", render_linkage_page(snapshot)
+        )
+
+    def test_handoff_fields_are_redacted(self):
+        comment = _cth(
+            2, created_at="2026-07-25T10:00:00Z", status="ok", next_owner="reviewer"
+        )
+        comment["body"] += "\nDecision: password=hunter2hunter2\n"
+        snapshot = _load(
+            [_issue(643)],
+            [_pr(902, body="Closes #643")],
+            pr=902,
+            comment_source=lambda kind, number: [comment],
+        )
+        self.assertNotIn("hunter2hunter2", json.dumps(snapshot_to_dict(snapshot)))
+        self.assertNotIn("hunter2hunter2", render_linkage_page(snapshot))
+
+    def test_html_escapes_markup_in_a_title(self):
+        snapshot = _load([_issue(643, title="<script>alert(1)</script>")], [])
+        html = render_linkage_page(snapshot)
+        self.assertNotIn("<script>alert(1)</script>", html)
+        self.assertIn("&lt;script&gt;", html)
+
+
+class TestLinkageRoutes(unittest.TestCase):
+    def setUp(self):
+        self.snapshot = _load(
+            [_issue(643, labels=("status:ready",))],
+            [_pr(902, body="Closes #643", labels=("status:pr-open",))],
+        )
+        self.client = TestClient(create_app())
+
+    def test_page_renders_both_tables(self):
+        with mock.patch("webui.app.load_linkage_snapshot", return_value=self.snapshot):
+            response = self.client.get("/gitea")
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("Issues → pull requests", response.text)
+        self.assertIn("Pull requests → issues", response.text)
+        self.assertIn("#643", response.text)
+
+    def test_api_exports_the_same_model(self):
+        with mock.patch("webui.app.load_linkage_snapshot", return_value=self.snapshot):
+            response = self.client.get("/api/v1/gitea/linkage")
+        self.assertEqual(response.status_code, 200)
+        payload = response.json()
+        self.assertTrue(payload["ok"])
+        self.assertEqual(payload["issues"][0]["linked_prs"], [902])
+        self.assertEqual(payload["prs"][0]["links"][0]["issue_number"], 643)
+        self.assertEqual(payload["schema_version"], 1)
+
+    def test_api_declares_the_evidence_vocabulary(self):
+        with mock.patch("webui.app.load_linkage_snapshot", return_value=self.snapshot):
+            payload = self.client.get("/api/v1/gitea/linkage").json()
+        names = {entry["name"] for entry in payload["evidence_kinds"]}
+        self.assertEqual(names, {EVIDENCE_CLOSES, EVIDENCE_BRANCH, EVIDENCE_REFERENCE})
+
+    def test_api_fails_closed_with_a_non_200_when_the_read_failed(self):
+        failed = _load([], [], project_id="no-such-project")
+        with mock.patch("webui.app.load_linkage_snapshot", return_value=failed):
+            response = self.client.get("/api/v1/gitea/linkage")
+        self.assertEqual(response.status_code, 502)
+        self.assertFalse(response.json()["ok"])
+
+    def test_page_still_renders_when_the_read_failed(self):
+        failed = _load([], [], project_id="no-such-project")
+        with mock.patch("webui.app.load_linkage_snapshot", return_value=failed):
+            response = self.client.get("/gitea")
+        self.assertEqual(response.status_code, 200)
+        self.assertIn("Linkage unavailable", response.text)
+
+    def test_query_parameters_reach_the_loader(self):
+        with mock.patch(
+            "webui.app.load_linkage_snapshot", return_value=self.snapshot
+        ) as loader:
+            self.client.get("/gitea?project=gitea-tools&state=all&pr=902")
+        loader.assert_called_once()
+        args, kwargs = loader.call_args
+        self.assertEqual(args[0], "gitea-tools")
+        self.assertEqual(kwargs["state"], "all")
+        self.assertEqual(kwargs["pr"], 902)
+        self.assertIsNone(kwargs["issue"])
+
+    def test_surface_stays_read_only(self):
+        for path in ("/gitea", "/api/v1/gitea/linkage"):
+            with self.subTest(path=path):
+                self.assertEqual(self.client.post(path).status_code, 405)
+
+    def test_nav_exposes_the_linkage_page_as_live(self):
+        self.assertIn("/gitea", nav_hrefs())
+        home = self.client.get("/").text
+        self.assertIn('href="/gitea"', home)
+        self.assertIn(">Gitea<", home)
+
+
+if __name__ == "__main__":
+    unittest.main()

webui/app.py

@@ -53,6 +53,11 @@ from webui.session_loader import (
     snapshot_to_dict as session_view_snapshot_to_dict,
 )
 from webui.session_views import render_sessions_page
+from webui.linkage_loader import (
+    load_linkage_snapshot,
+    snapshot_to_dict as linkage_snapshot_to_dict,
+)
+from webui.linkage_views import render_linkage_page
 from webui.inventory import (
     SECTION_NAMES as _INVENTORY_SECTIONS,
     load_inventory_snapshot,
@@ -342,6 +347,41 @@ async def api_sessions(_request: Request) -> JSONResponse:
     return JSONResponse(session_view_snapshot_to_dict(load_session_view_snapshot()))
 
 
+def _linkage_snapshot(request: Request):
+    """Load one linkage snapshot from the request's scope and focus parameters."""
+    return load_linkage_snapshot(
+        request.query_params.get("project") or None,
+        state=request.query_params.get("state"),
+        issue=_query_int(request, "issue"),
+        pr=_query_int(request, "pr"),
+    )
+
+
+async def gitea_linkage(request: Request) -> HTMLResponse:
+    """Gitea issue↔PR linkage console (#645) — read-only.
+
+    Always 200, including on a failed read: this is an operator view, and it
+    must render *why* linkage could not be loaded rather than withhold the page.
+    The snapshot itself carries ``ok=False`` and the page refuses to draw a
+    linkage table it cannot stand behind.
+    """
+    return HTMLResponse(render_linkage_page(_linkage_snapshot(request)))
+
+
+async def api_v1_gitea_linkage(request: Request) -> JSONResponse:
+    """JSON export of the issue↔PR linkage model (#645).
+
+    Unlike the HTML view, the API answers with 502 when the snapshot could not
+    be loaded, so an automated consumer cannot read a fail-closed payload as a
+    successful "no links exist" result.
+    """
+    snapshot = _linkage_snapshot(request)
+    return JSONResponse(
+        linkage_snapshot_to_dict(snapshot),
+        status_code=200 if snapshot.ok else 502,
+    )
+
+
 async def _parse_audit_form(request: Request) -> tuple[str, str | None]:
     if request.method == "GET":
         return "", None
@@ -785,6 +825,8 @@ def create_app(*, bind_host: str | None = None) -> Starlette:
             Route("/api/sessions", api_sessions, methods=["GET"]),
             Route("/api/v1/sessions", api_sessions, methods=["GET"]),
             Route("/api/v1/timeline", api_v1_timeline, methods=["GET"]),
+            Route("/gitea", gitea_linkage, methods=["GET"]),
+            Route("/api/v1/gitea/linkage", api_v1_gitea_linkage, methods=["GET"]),
             Route("/analytics", analytics, methods=["GET"]),
             Route("/api/analytics", api_v1_analytics, methods=["GET"]),
             Route("/api/v1/analytics", api_v1_analytics, methods=["GET"]),

webui/linkage_loader.py

@@ -0,0 +1,771 @@
+"""Gitea issue↔PR linkage model for the console (#645, Phase 3).
+
+Operators lose context between an issue and the PR that closes it: which PR
+carries which issue, whether two PRs claim the same issue, and what the latest
+canonical handoff on that thread said. The evidence exists in Gitea, but only
+as free text scattered across PR titles, bodies, and branch names.
+
+This module resolves that linkage into one read-only model:
+
+* :func:`resolve_linkage` is a pure function from raw Gitea issue/PR payloads to
+  a :class:`LinkageIndex`. It records *how* each edge was found (a ``Closes #N``
+  keyword, the canonical ``feat/issue-N-…`` branch marker, or a bare ``#N``
+  body reference) and never collapses several candidates into one silent guess.
+* :func:`load_linkage_snapshot` scopes that index to a registry project and
+  optionally attaches the latest Canonical Thread Handoff (CTH) summary for one
+  focused issue or PR.
+
+Design rules, matching the rest of the console:
+
+- **Read-only.** Gitea is read through the shared authenticated helpers. No
+  endpoint here mutates anything, and no write action is registered.
+- **Qualified absence.** Linkage is a claim about a *loaded* window of Gitea.
+  When pagination did not complete, when credentials were unavailable, or when
+  only open items were fetched, the snapshot says so and every "no linked PR"
+  is marked non-authoritative. An empty edge list from a partial read is not
+  evidence that no link exists.
+- **Handoff is loaded, never assumed.** CTH comments are thread-scoped, so they
+  are fetched only for an explicitly focused issue or PR. Every other row
+  reports ``not_loaded`` rather than rendering as "no handoff".
+- **Redaction at the boundary.** Titles, labels, handoff fields, and error
+  reasons are free text from Gitea and cross :mod:`webui.console_redaction`
+  before they leave this module.
+- **Deep links are opt-in.** A link to the Gitea web UI is emitted only under
+  the ``GITEA_MCP_REVEAL_ENDPOINTS`` admin opt-in, exactly as the MCP tools
+  gate their own URL exposure.
+
+Non-goals (from the issue): no issue/PR editor, no browser review or merge, no
+reimplementation of Gitea search.
+"""
+
+from __future__ import annotations
+
+import os
+import re
+from dataclasses import dataclass
+from typing import Any, Callable, Iterable, Sequence
+
+from gitea_auth import api_fetch_page, get_auth_header, gitea_url, repo_api_url
+
+from webui import console_redaction
+from webui.project_registry import ProjectRecord, load_registry
+from webui.queue_loader import (
+    PaginationMeta,
+    _fetch_issues,
+    _fetch_prs,
+    _host_from_url,
+)
+
+#: Version of the serialized linkage contract. Bump on any breaking change.
+LINKAGE_SCHEMA_VERSION = 1
+
+# --- Linkage evidence -------------------------------------------------------
+# Ordered strongest to weakest. The strength ordering is what makes an
+# ambiguous PR detectable: two candidates at the same strength are a genuine
+# ambiguity, while a weaker candidate alongside a stronger one is not.
+EVIDENCE_CLOSES = "closes_keyword"
+EVIDENCE_BRANCH = "branch_marker"
+EVIDENCE_REFERENCE = "body_reference"
+
+EVIDENCE_ORDER: tuple[str, ...] = (
+    EVIDENCE_CLOSES,
+    EVIDENCE_BRANCH,
+    EVIDENCE_REFERENCE,
+)
+_EVIDENCE_RANK = {name: rank for rank, name in enumerate(EVIDENCE_ORDER)}
+
+EVIDENCE_DESCRIPTIONS: dict[str, str] = {
+    EVIDENCE_CLOSES: (
+        "the PR title or body declares 'closes/fixes/resolves #N' — Gitea itself "
+        "acts on this keyword, so it is the strongest available evidence"
+    ),
+    EVIDENCE_BRANCH: (
+        "the PR head branch carries the canonical issue marker "
+        "'(fix|feat|docs|chore)/issue-N-…' minted by the issue lock"
+    ),
+    EVIDENCE_REFERENCE: (
+        "the PR body mentions '#N' without a closing keyword; a mention is not "
+        "a claim that the PR closes that issue"
+    ),
+}
+
+_CLOSES_RE = re.compile(r"(?:closes|fixes|resolves)\s+#(\d+)", re.IGNORECASE)
+_REFERENCE_RE = re.compile(r"#(\d+)")
+_BRANCH_MARKER_RE = re.compile(
+    r"^(?:fix|feat|docs|chore)/issue-(\d+)(?:[-/]|$)", re.IGNORECASE
+)
+
+# Handoff-source states. ``not_loaded`` is deliberately distinct from "none
+# found": a row whose comments were never fetched proves nothing about whether
+# a handoff exists on that thread.
+HANDOFF_NOT_LOADED = "not_loaded"
+HANDOFF_LOADED = "loaded"
+HANDOFF_UNAVAILABLE = "unavailable"
+
+# Which item states were fetched. Linkage claims are scoped to this window.
+STATE_OPEN = "open"
+STATE_ALL = "all"
+_SUPPORTED_STATES = (STATE_OPEN, STATE_ALL)
+
+
+def _redact(value: Any) -> Any:
+    """Redact one free-text field, failing closed to the placeholder."""
+    if value is None:
+        return None
+    return console_redaction.redact_text(str(value))
+
+
+def deep_links_enabled(env: dict[str, str] | None = None) -> bool:
+    """Whether Gitea web-UI deep links may be emitted (admin/debug opt-in)."""
+    source = env if env is not None else os.environ
+    return (source.get("GITEA_MCP_REVEAL_ENDPOINTS") or "").strip().lower() in {
+        "1",
+        "true",
+        "yes",
+        "on",
+    }
+
+
+def _deep_link(host: str, org: str, repo: str, kind: str, number: int) -> str | None:
+    """Build a Gitea web link for one item, or None when reveal is not enabled."""
+    if not deep_links_enabled() or not (host and org and repo):
+        return None
+    segment = "pulls" if kind == "pr" else "issues"
+    try:
+        return gitea_url(host, f"/{org}/{repo}/{segment}/{int(number)}")
+    except Exception:
+        return None
+
+
+# --- Pure linkage resolution -------------------------------------------------
+
+
+@dataclass(frozen=True)
+class IssueLink:
+    """One resolved edge from a PR to an issue, with the evidence that found it."""
+
+    issue_number: int
+    evidence: tuple[str, ...]
+
+    @property
+    def strength(self) -> int:
+        """Rank of the strongest evidence backing this edge (lower is stronger)."""
+        return min(
+            (_EVIDENCE_RANK.get(name, len(EVIDENCE_ORDER)) for name in self.evidence),
+            default=len(EVIDENCE_ORDER),
+        )
+
+    @property
+    def closes(self) -> bool:
+        """True only when the PR *declares* it closes the issue."""
+        return EVIDENCE_CLOSES in self.evidence
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "issue_number": self.issue_number,
+            "evidence": list(self.evidence),
+            "closes": self.closes,
+        }
+
+
+def _sorted_links(links: Iterable[IssueLink]) -> tuple[IssueLink, ...]:
+    return tuple(sorted(links, key=lambda link: (link.strength, link.issue_number)))
+
+
+def resolve_pr_links(pr: dict[str, Any]) -> tuple[IssueLink, ...]:
+    """Resolve every issue a PR points at, strongest evidence first.
+
+    Every candidate is kept. Collapsing to a single "linked issue" is what makes
+    a mislinked or double-claimed PR invisible, so the caller decides what to do
+    with several candidates rather than being handed one guess.
+    """
+    found: dict[int, set[str]] = {}
+
+    def _add(number: Any, evidence: str) -> None:
+        try:
+            issue_number = int(number)
+        except (TypeError, ValueError):
+            return
+        if issue_number <= 0:
+            return
+        found.setdefault(issue_number, set()).add(evidence)
+
+    title = str(pr.get("title") or "")
+    body = str(pr.get("body") or "")
+    for text in (title, body):
+        for match in _CLOSES_RE.finditer(text):
+            _add(match.group(1), EVIDENCE_CLOSES)
+
+    head_ref = str((pr.get("head") or {}).get("ref") or "")
+    branch_match = _BRANCH_MARKER_RE.match(head_ref.strip())
+    if branch_match:
+        _add(branch_match.group(1), EVIDENCE_BRANCH)
+
+    # The ``#N`` inside "Closes #N" is the *same* textual occurrence as the
+    # closing keyword, not a second, independent mention. Blanking the closing
+    # phrases first keeps "mention" meaning what the legend says it means: a
+    # reference the PR made without claiming to close anything.
+    for match in _REFERENCE_RE.finditer(_CLOSES_RE.sub(" ", body)):
+        _add(match.group(1), EVIDENCE_REFERENCE)
+
+    # A PR's own number appearing in its body is self-reference, not linkage.
+    try:
+        found.pop(int(pr.get("number")), None)
+    except (TypeError, ValueError):
+        pass
+
+    return _sorted_links(
+        IssueLink(
+            issue_number=number,
+            evidence=tuple(name for name in EVIDENCE_ORDER if name in evidence),
+        )
+        for number, evidence in found.items()
+    )
+
+
+@dataclass(frozen=True)
+class LinkageIndex:
+    """Resolved linkage over one loaded window of issues and PRs."""
+
+    pr_links: dict[int, tuple[IssueLink, ...]]
+    issue_prs: dict[int, tuple[int, ...]]
+
+    def primary_issue(self, pr_number: int) -> IssueLink | None:
+        """The strongest edge for a PR, or None when it points at no issue."""
+        links = self.pr_links.get(int(pr_number)) or ()
+        return links[0] if links else None
+
+    def ambiguous(self, pr_number: int) -> bool:
+        """True when two or more issues tie at the PR's strongest evidence."""
+        links = self.pr_links.get(int(pr_number)) or ()
+        if len(links) < 2:
+            return False
+        best = links[0].strength
+        return sum(1 for link in links if link.strength == best) > 1
+
+    def contested_issues(self) -> tuple[int, ...]:
+        """Issues claimed by more than one PR in the loaded window."""
+        return tuple(
+            number for number, prs in sorted(self.issue_prs.items()) if len(prs) > 1
+        )
+
+
+def resolve_linkage(prs: Sequence[dict[str, Any]]) -> LinkageIndex:
+    """Build the bidirectional linkage index for a loaded window of PRs.
+
+    Only *closing* and *branch-marker* edges populate the issue→PR direction: a
+    bare ``#N`` mention is a reference, and treating it as "this PR is the work
+    for issue N" would invent contested issues out of ordinary cross-links. The
+    weaker edge stays visible on the PR→issue side, where it is labelled.
+    """
+    pr_links: dict[int, tuple[IssueLink, ...]] = {}
+    issue_prs: dict[int, list[int]] = {}
+    for pr in prs or []:
+        try:
+            pr_number = int(pr["number"])
+        except (KeyError, TypeError, ValueError):
+            continue
+        links = resolve_pr_links(pr)
+        pr_links[pr_number] = links
+        for link in links:
+            if link.evidence == (EVIDENCE_REFERENCE,):
+                continue
+            bucket = issue_prs.setdefault(link.issue_number, [])
+            if pr_number not in bucket:
+                bucket.append(pr_number)
+    return LinkageIndex(
+        pr_links=pr_links,
+        issue_prs={number: tuple(sorted(items)) for number, items in issue_prs.items()},
+    )
+
+
+# --- Canonical handoff summary ----------------------------------------------
+
+
+@dataclass(frozen=True)
+class HandoffSummary:
+    """The latest CTH comment on one thread, redacted for display."""
+
+    comment_id: int | None
+    created_at: str | None
+    author: str | None
+    cth_type: str
+    cth_type_known: bool
+    status: str | None
+    next_owner: str | None
+    current_blocker: str | None
+    decision: str | None
+    next_action: str | None
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "comment_id": self.comment_id,
+            "created_at": self.created_at,
+            "author": self.author,
+            "cth_type": self.cth_type,
+            "cth_type_known": self.cth_type_known,
+            "status": self.status,
+            "next_owner": self.next_owner,
+            "current_blocker": self.current_blocker,
+            "decision": self.decision,
+            "next_action": self.next_action,
+        }
+
+
+@dataclass(frozen=True)
+class HandoffStatus:
+    """Why a thread's handoff summary is present, absent, or unknown."""
+
+    state: str
+    reason: str | None = None
+    target: str | None = None
+
+    @property
+    def loaded(self) -> bool:
+        return self.state == HANDOFF_LOADED
+
+    def to_dict(self) -> dict[str, Any]:
+        return {"state": self.state, "reason": self.reason, "target": self.target}
+
+
+def summarize_handoff(comments: Sequence[dict[str, Any]]) -> HandoffSummary | None:
+    """Summarize the newest CTH comment in *comments*, or None when there is none.
+
+    Every field is redacted before it is returned: a handoff body is operator
+    free text that regularly quotes commands, and it is rendered verbatim on the
+    page this feeds.
+    """
+    from canonical_thread_handoff import find_latest_cth, is_known_cth_type
+
+    try:
+        latest = find_latest_cth(list(comments or []))
+    except Exception:
+        return None
+    if not latest:
+        return None
+    fields = latest.get("fields") or {}
+    cth_type = str(latest.get("cth_type") or "").strip()
+    known = is_known_cth_type(cth_type)
+    try:
+        comment_id: int | None = int(latest.get("comment_id"))
+    except (TypeError, ValueError):
+        comment_id = None
+    return HandoffSummary(
+        comment_id=comment_id,
+        created_at=_redact(latest.get("created_at")),
+        author=_redact(latest.get("author")),
+        # An unrecognised heading is reported as such rather than republished:
+        # the heading is free text, and CTH_TYPES is the only authority for what
+        # a handoff type may be.
+        cth_type=cth_type if known else "unrecognized",
+        cth_type_known=known,
+        status=_redact(fields.get("status")),
+        next_owner=_redact(fields.get("next owner")),
+        current_blocker=_redact(fields.get("current blocker")),
+        decision=_redact(fields.get("decision")),
+        next_action=_redact(fields.get("next action")),
+    )
+
+
+CommentSource = Callable[[str, int], list[dict[str, Any]]]
+
+
+def build_comment_source(host: str, org: str, repo: str) -> CommentSource | None:
+    """Build an authenticated ``(kind, number) -> comments`` fetcher, or None.
+
+    Returns None when the console is running in offline test mode or when no
+    credential is available for *host*, so the caller reports the handoff source
+    as unavailable instead of as an empty thread.
+    """
+    if _offline_test_mode() or not (host and org and repo):
+        return None
+    auth = get_auth_header(host)
+    if not auth:
+        return None
+
+    def _fetch(kind: str, number: int) -> list[dict[str, Any]]:
+        segment = "pulls" if kind == "pr" else "issues"
+        url = f"{repo_api_url(host, org, repo)}/{segment}/{int(number)}/comments"
+        comments: list[dict[str, Any]] = []
+        page = 1
+        while page <= 20:
+            raw, meta = api_fetch_page(url, auth, page=page, limit=50)
+            comments.extend(raw)
+            if bool(meta["is_final_page"]):
+                break
+            page += 1
+        return comments
+
+    return _fetch
+
+
+# --- Snapshot ----------------------------------------------------------------
+
+
+@dataclass(frozen=True)
+class LinkageNode:
+    """One issue or PR row with its resolved links and display metadata."""
+
+    kind: str
+    number: int
+    title: str
+    state: str
+    labels: tuple[str, ...] = ()
+    links: tuple[IssueLink, ...] = ()
+    linked_prs: tuple[int, ...] = ()
+    ambiguous: bool = False
+    contested: bool = False
+    deep_link: str | None = None
+    handoff: HandoffSummary | None = None
+    handoff_status: HandoffStatus = HandoffStatus(HANDOFF_NOT_LOADED)
+    links_authoritative: bool = True
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "kind": self.kind,
+            "number": self.number,
+            "title": self.title,
+            "state": self.state,
+            "labels": list(self.labels),
+            "links": [link.to_dict() for link in self.links],
+            "linked_prs": list(self.linked_prs),
+            "ambiguous": self.ambiguous,
+            "contested": self.contested,
+            "deep_link": self.deep_link,
+            "links_authoritative": self.links_authoritative,
+            "handoff": self.handoff.to_dict() if self.handoff else None,
+            "handoff_status": self.handoff_status.to_dict(),
+        }
+
+
+@dataclass(frozen=True)
+class LinkageSnapshot:
+    """One answered linkage query over a scoped window of a Gitea repo."""
+
+    ok: bool
+    project_id: str
+    repo_label: str
+    host: str
+    state_scope: str
+    issues: tuple[LinkageNode, ...] = ()
+    prs: tuple[LinkageNode, ...] = ()
+    contested_issues: tuple[int, ...] = ()
+    focus: tuple[str, int] | None = None
+    inventory_complete: bool = False
+    deep_links_enabled: bool = False
+    handoff_status: HandoffStatus = HandoffStatus(HANDOFF_NOT_LOADED)
+    fetch_error: str | None = None
+
+    @property
+    def orphan_prs(self) -> tuple[LinkageNode, ...]:
+        """PRs in the loaded window that point at no issue at all."""
+        return tuple(node for node in self.prs if not node.links)
+
+    def to_dict(self) -> dict[str, Any]:
+        return {
+            "ok": self.ok,
+            "schema_version": LINKAGE_SCHEMA_VERSION,
+            "project_id": self.project_id,
+            "repo": self.repo_label,
+            "state_scope": self.state_scope,
+            "inventory_complete": self.inventory_complete,
+            "deep_links_enabled": self.deep_links_enabled,
+            "focus": (
+                None
+                if self.focus is None
+                else {"kind": self.focus[0], "number": self.focus[1]}
+            ),
+            "handoff_source": self.handoff_status.to_dict(),
+            "fetch_error": self.fetch_error,
+            "contested_issues": list(self.contested_issues),
+            "issues": [node.to_dict() for node in self.issues],
+            "prs": [node.to_dict() for node in self.prs],
+            "evidence_kinds": [
+                {"name": name, "description": EVIDENCE_DESCRIPTIONS[name]}
+                for name in EVIDENCE_ORDER
+            ],
+        }
+
+
+def snapshot_to_dict(snapshot: LinkageSnapshot) -> dict[str, Any]:
+    """JSON-serializable export for ``/api/v1/gitea/linkage``."""
+    return snapshot.to_dict()
+
+
+def _offline_test_mode() -> bool:
+    return (os.environ.get("WEBUI_TEST_OFFLINE") or "").strip().lower() in {
+        "1",
+        "true",
+        "yes",
+    }
+
+
+def _labels_of(item: dict[str, Any]) -> tuple[str, ...]:
+    return tuple(
+        str(_redact(label.get("name")))
+        for label in (item.get("labels") or [])
+        if label.get("name")
+    )
+
+
+def _failed_snapshot(
+    *,
+    project_id: str,
+    repo_label: str,
+    host: str,
+    state_scope: str,
+    reason: str,
+) -> LinkageSnapshot:
+    """A read that could not be answered. Never an empty-and-healthy snapshot."""
+    return LinkageSnapshot(
+        ok=False,
+        project_id=project_id,
+        repo_label=repo_label,
+        host=host,
+        state_scope=state_scope,
+        inventory_complete=False,
+        deep_links_enabled=deep_links_enabled(),
+        handoff_status=HandoffStatus(
+            HANDOFF_UNAVAILABLE, reason="linkage inventory could not be loaded"
+        ),
+        fetch_error=str(_redact(reason)),
+    )
+
+
+def _resolve_project(project_id: str | None) -> ProjectRecord | None:
+    registry = load_registry()
+    if project_id:
+        for entry in registry.projects:
+            if entry.id == project_id:
+                return entry
+        return None
+    return registry.projects[0] if registry.projects else None
+
+
+def _normalize_state(state: str | None) -> str:
+    text = (state or STATE_OPEN).strip().lower()
+    return text if text in _SUPPORTED_STATES else STATE_OPEN
+
+
+def load_linkage_snapshot(
+    project_id: str | None = None,
+    *,
+    state: str | None = None,
+    issue: int | None = None,
+    pr: int | None = None,
+    fetch_prs: Callable[..., tuple[list[dict], PaginationMeta]] | None = None,
+    fetch_issues: Callable[..., tuple[list[dict], PaginationMeta]] | None = None,
+    comment_source: CommentSource | None = None,
+) -> LinkageSnapshot:
+    """Load issue↔PR linkage for a registry project.
+
+    ``issue``/``pr`` focus one thread: the focused row is the only one whose
+    Canonical Thread Handoff comments are fetched, because handoff comments are
+    thread-scoped and loading them for a whole queue would be one request per
+    row. Every unfocused row reports its handoff as ``not_loaded``.
+    """
+    state_scope = _normalize_state(state)
+    try:
+        project = _resolve_project(project_id)
+    except Exception as exc:  # registry invalid — fail closed with the reason
+        return _failed_snapshot(
+            project_id=project_id or "",
+            repo_label="",
+            host="",
+            state_scope=state_scope,
+            reason=f"project registry unavailable: {exc}",
+        )
+
+    if project is None:
+        return _failed_snapshot(
+            project_id=project_id or "",
+            repo_label="",
+            host="",
+            state_scope=state_scope,
+            reason=(
+                f"project {project_id!r} not found in registry"
+                if project_id
+                else "no projects registered"
+            ),
+        )
+
+    host = _host_from_url(project.remote_host)
+    repo_label = f"{project.gitea_owner}/{project.repo_name}"
+    offline_test = _offline_test_mode()
+
+    def _empty_fetch(*_args, **_kwargs):
+        return [], PaginationMeta(
+            page=1,
+            per_page=50,
+            returned_count=0,
+            has_more=False,
+            is_final_page=True,
+            # An offline stub loaded nothing; claiming a complete inventory here
+            # would let the page assert that no issue has a linked PR.
+            inventory_complete=False,
+            pages_fetched=0,
+        )
+
+    pr_fetch = fetch_prs or (_empty_fetch if offline_test else _fetch_prs)
+    issue_fetch = fetch_issues or (_empty_fetch if offline_test else _fetch_issues)
+    using_live_fetch = not offline_test and (fetch_prs is None or fetch_issues is None)
+    auth = get_auth_header(host) if using_live_fetch else "test-auth"
+    if using_live_fetch and not auth:
+        return _failed_snapshot(
+            project_id=project.id,
+            repo_label=repo_label,
+            host=host,
+            state_scope=state_scope,
+            reason=(
+                f"Gitea credentials unavailable for {host}; linkage cannot be "
+                "loaded (fail closed — not rendering an empty linkage table)"
+            ),
+        )
+
+    try:
+        raw_prs, pr_pagination = pr_fetch(
+            host, project.gitea_owner, project.repo_name, auth, state=state_scope
+        )
+        raw_issues, issue_pagination = issue_fetch(
+            host, project.gitea_owner, project.repo_name, auth, state=state_scope
+        )
+    except Exception as exc:  # noqa: BLE001 — operator-visible fetch failure
+        return _failed_snapshot(
+            project_id=project.id,
+            repo_label=repo_label,
+            host=host,
+            state_scope=state_scope,
+            reason=f"Gitea fetch failed: {exc}",
+        )
+
+    inventory_complete = bool(
+        getattr(pr_pagination, "inventory_complete", False)
+        and getattr(issue_pagination, "inventory_complete", False)
+    )
+
+    index = resolve_linkage(raw_prs)
+    contested = index.contested_issues()
+
+    focus: tuple[str, int] | None = None
+    if pr is not None:
+        focus = ("pr", int(pr))
+    elif issue is not None:
+        focus = ("issue", int(issue))
+
+    unfocused_reason = (
+        "canonical handoff comments are thread-scoped; focus one issue or PR "
+        "to load its latest handoff"
+    )
+    handoff_status = HandoffStatus(HANDOFF_NOT_LOADED, reason=unfocused_reason)
+    focus_handoff: HandoffSummary | None = None
+    if focus is not None:
+        source = comment_source
+        if source is None and not offline_test:
+            source = build_comment_source(host, project.gitea_owner, project.repo_name)
+        target = f"{focus[0]}#{focus[1]}"
+        if source is None:
+            handoff_status = HandoffStatus(
+                HANDOFF_UNAVAILABLE,
+                reason="no authenticated comment source available for this read",
+                target=target,
+            )
+        else:
+            try:
+                focus_handoff = summarize_handoff(source(focus[0], focus[1]) or [])
+                handoff_status = HandoffStatus(HANDOFF_LOADED, target=target)
+            except Exception as exc:  # fail soft: degrade this source only
+                handoff_status = HandoffStatus(
+                    HANDOFF_UNAVAILABLE,
+                    reason=str(_redact(f"handoff fetch failed: {exc}")),
+                    target=target,
+                )
+
+    def _node_handoff(
+        kind: str, number: int
+    ) -> tuple[HandoffSummary | None, HandoffStatus]:
+        """Attach the handoff only to the focused row; qualify every other row."""
+        if focus == (kind, number):
+            return (focus_handoff, handoff_status)
+        return (
+            None,
+            HandoffStatus(
+                HANDOFF_NOT_LOADED,
+                reason=unfocused_reason if focus is None else "not the focused thread",
+            ),
+        )
+
+    def _number_of(raw: dict[str, Any]) -> int | None:
+        try:
+            return int(raw["number"])
+        except (KeyError, TypeError, ValueError):
+            return None
+
+    def _sort_key(raw: dict[str, Any]) -> int:
+        number = _number_of(raw)
+        return -1 if number is None else number
+
+    issue_nodes: list[LinkageNode] = []
+    for raw in sorted(raw_issues or [], key=_sort_key, reverse=True):
+        number = _number_of(raw)
+        if number is None:
+            continue
+        node_handoff, node_status = _node_handoff("issue", number)
+        linked_prs = index.issue_prs.get(number, ())
+        issue_nodes.append(
+            LinkageNode(
+                kind="issue",
+                number=number,
+                title=str(_redact(raw.get("title")) or ""),
+                state=str(raw.get("state") or ""),
+                labels=_labels_of(raw),
+                linked_prs=linked_prs,
+                contested=len(linked_prs) > 1,
+                deep_link=_deep_link(
+                    host, project.gitea_owner, project.repo_name, "issue", number
+                ),
+                handoff=node_handoff,
+                handoff_status=node_status,
+                links_authoritative=inventory_complete,
+            )
+        )
+
+    pr_nodes: list[LinkageNode] = []
+    for raw in sorted(raw_prs or [], key=_sort_key, reverse=True):
+        number = _number_of(raw)
+        if number is None:
+            continue
+        node_handoff, node_status = _node_handoff("pr", number)
+        links = index.pr_links.get(number, ())
+        pr_nodes.append(
+            LinkageNode(
+                kind="pr",
+                number=number,
+                title=str(_redact(raw.get("title")) or ""),
+                state=str(raw.get("state") or ""),
+                labels=_labels_of(raw),
+                links=links,
+                ambiguous=index.ambiguous(number),
+                contested=any(link.issue_number in contested for link in links),
+                deep_link=_deep_link(
+                    host, project.gitea_owner, project.repo_name, "pr", number
+                ),
+                handoff=node_handoff,
+                handoff_status=node_status,
+                links_authoritative=inventory_complete,
+            )
+        )
+
+    return LinkageSnapshot(
+        ok=True,
+        project_id=project.id,
+        repo_label=repo_label,
+        host=host,
+        state_scope=state_scope,
+        issues=tuple(issue_nodes),
+        prs=tuple(pr_nodes),
+        contested_issues=contested,
+        focus=focus,
+        inventory_complete=inventory_complete,
+        deep_links_enabled=deep_links_enabled(),
+        handoff_status=handoff_status,
+    )

webui/linkage_views.py

@@ -0,0 +1,364 @@
+"""HTML views for the Gitea issue↔PR linkage console (#645, Phase 3).
+
+Read-only renderer over :mod:`webui.linkage_loader`. The page's job is to make
+three things impossible to misread:
+
+* **why** an edge exists — every link carries its evidence badge, so a bare
+  ``#N`` mention never looks like a closing claim;
+* **what was not loaded** — a partial inventory, an unfocused thread, or an
+  unavailable handoff source renders as an explicit qualifier, never as an
+  affirmative "none";
+* **that nothing here mutates** — there is no review, merge, or edit control,
+  and the deep link out to Gitea appears only under the admin reveal opt-in.
+"""
+
+from __future__ import annotations
+
+from html import escape
+from typing import Sequence
+
+from webui.layout import render_page
+from webui.linkage_loader import (
+    EVIDENCE_BRANCH,
+    EVIDENCE_CLOSES,
+    EVIDENCE_DESCRIPTIONS,
+    EVIDENCE_ORDER,
+    EVIDENCE_REFERENCE,
+    HANDOFF_LOADED,
+    HANDOFF_NOT_LOADED,
+    HandoffSummary,
+    LinkageNode,
+    LinkageSnapshot,
+)
+
+_EVIDENCE_CSS = {
+    EVIDENCE_CLOSES: "badge-health-ok",
+    EVIDENCE_BRANCH: "badge-health-skipped",
+    EVIDENCE_REFERENCE: "badge-health-unproven",
+}
+
+_EVIDENCE_LABEL = {
+    EVIDENCE_CLOSES: "closes",
+    EVIDENCE_BRANCH: "branch",
+    EVIDENCE_REFERENCE: "mention",
+}
+
+
+def _badge(text: str, css: str) -> str:
+    return f'<span class="badge {css}">{escape(text)}</span>'
+
+
+def _labels(names: Sequence[str]) -> str:
+    if not names:
+        return '<span class="muted">—</span>'
+    return " ".join(_badge(name, "badge-health-skipped") for name in names)
+
+
+def _ref(node: LinkageNode) -> str:
+    """Render an item reference, hyperlinked only when deep links are revealed."""
+    label = f"#{node.number}"
+    if node.deep_link:
+        return f'<a href="{escape(node.deep_link)}"><code>{escape(label)}</code></a>'
+    return f"<code>{escape(label)}</code>"
+
+
+def _scope_card(snapshot: LinkageSnapshot) -> str:
+    focus = (
+        "none"
+        if snapshot.focus is None
+        else f"{snapshot.focus[0]}#{snapshot.focus[1]}"
+    )
+    completeness = (
+        _badge("complete", "badge-health-ok")
+        if snapshot.inventory_complete
+        else _badge("partial", "badge-health-degraded")
+    )
+    links_note = (
+        "Every linkage edge below is a claim about this loaded window only."
+        if snapshot.inventory_complete
+        else (
+            "Pagination did not complete for this window, so an empty link list "
+            "means <em>none found in what was loaded</em> — not that no link exists."
+        )
+    )
+    deep_links = (
+        _badge("enabled", "badge-health-ok")
+        if snapshot.deep_links_enabled
+        else _badge("hidden", "badge-health-skipped")
+    )
+    return f"""<div class="health-card">
+  <h3>Scope</h3>
+  <table class="detail">
+    <tr><th>Project</th><td><code>{escape(snapshot.project_id or "—")}</code></td></tr>
+    <tr><th>Repository</th><td><code>{escape(snapshot.repo_label or "—")}</code></td></tr>
+    <tr><th>Item state</th><td><code>{escape(snapshot.state_scope)}</code></td></tr>
+    <tr><th>Focused thread</th><td><code>{escape(focus)}</code></td></tr>
+    <tr><th>Inventory</th><td>{completeness}</td></tr>
+    <tr><th>Gitea deep links</th><td>{deep_links}</td></tr>
+  </table>
+  <p class="muted">{links_note}</p>
+</div>"""
+
+
+def _error_card(snapshot: LinkageSnapshot) -> str:
+    if snapshot.ok and not snapshot.fetch_error:
+        return ""
+    return (
+        '<div class="health-card health-stale"><strong>Linkage unavailable:</strong> '
+        f"{escape(snapshot.fetch_error or 'the linkage read did not complete')}. "
+        "No linkage table is rendered: an empty table would read as "
+        "<em>no issue is linked to any PR</em>, which this read cannot claim."
+        "</div>"
+    )
+
+
+def _contested_card(snapshot: LinkageSnapshot) -> str:
+    if not snapshot.contested_issues:
+        return ""
+    refs = ", ".join(f"<code>#{number}</code>" for number in snapshot.contested_issues)
+    return (
+        '<div class="health-card health-stale">'
+        f"<strong>Contested issues:</strong> {refs}. More than one PR in this "
+        "window claims each of these — duplicate work or a superseded PR. "
+        "Resolution stays in Gitea and the workflow; this console only reports it."
+        "</div>"
+    )
+
+
+def _evidence_badges(evidence: Sequence[str]) -> str:
+    return " ".join(
+        _badge(
+            _EVIDENCE_LABEL.get(name, name),
+            _EVIDENCE_CSS.get(name, "badge-health-skipped"),
+        )
+        for name in EVIDENCE_ORDER
+        if name in evidence
+    )
+
+
+def _handoff_inline(handoff: HandoffSummary) -> str:
+    type_css = "badge-health-ok" if handoff.cth_type_known else "badge-health-degraded"
+    return (
+        f'{_badge(handoff.cth_type or "—", type_css)}'
+        f'<div class="muted" style="font-size:0.82rem;">'
+        f'{escape(handoff.status or "—")} → {escape(handoff.next_owner or "—")}</div>'
+    )
+
+
+def _handoff_cell(node: LinkageNode) -> str:
+    """Render the handoff column, distinguishing 'none found' from 'not loaded'."""
+    status = node.handoff_status
+    if status.state == HANDOFF_LOADED:
+        if node.handoff is None:
+            return '<span class="muted">no canonical handoff on this thread</span>'
+        return _handoff_inline(node.handoff)
+    if status.state == HANDOFF_NOT_LOADED:
+        return (
+            f'{_badge("not loaded", "badge-health-skipped")}'
+            f'<div class="muted" style="font-size:0.82rem;">'
+            f'{escape(status.reason or "")}</div>'
+        )
+    return (
+        f'{_badge("unavailable", "badge-health-degraded")}'
+        f'<div class="muted" style="font-size:0.82rem;">'
+        f'{escape(status.reason or "")}</div>'
+    )
+
+
+def _issue_rows(snapshot: LinkageSnapshot) -> str:
+    rows = []
+    for node in snapshot.issues:
+        if node.linked_prs:
+            linked = ", ".join(f"<code>#{number}</code>" for number in node.linked_prs)
+            if node.contested:
+                linked += " " + _badge("contested", "badge-blocked")
+        elif node.links_authoritative:
+            linked = '<span class="muted">none</span>'
+        else:
+            # The distinction an operator needs: nothing found in a window that
+            # was not fully loaded is not the same as nothing existing.
+            linked = '<span class="muted">none found (partial inventory)</span>'
+        rows.append(
+            "<tr>"
+            f"<td>{_ref(node)}</td>"
+            f"<td>{escape(node.title)}</td>"
+            f"<td>{escape(node.state or '—')}</td>"
+            f"<td>{_labels(node.labels)}</td>"
+            f"<td>{linked}</td>"
+            f"<td>{_handoff_cell(node)}</td>"
+            "</tr>"
+        )
+    if not rows:
+        return '<tr><td colspan="6" class="muted">No issues in the loaded window.</td></tr>'
+    return "".join(rows)
+
+
+def _pr_rows(snapshot: LinkageSnapshot) -> str:
+    rows = []
+    for node in snapshot.prs:
+        if node.links:
+            linked = "".join(
+                f"<div><code>#{link.issue_number}</code> "
+                f"{_evidence_badges(link.evidence)}</div>"
+                for link in node.links
+            )
+            if node.ambiguous:
+                linked += _badge("ambiguous", "badge-blocked")
+            if node.contested:
+                linked += " " + _badge("contested", "badge-blocked")
+        elif node.links_authoritative:
+            linked = '<span class="muted">no issue reference</span>'
+        else:
+            linked = '<span class="muted">none found (partial inventory)</span>'
+        rows.append(
+            "<tr>"
+            f"<td>{_ref(node)}</td>"
+            f"<td>{escape(node.title)}</td>"
+            f"<td>{escape(node.state or '—')}</td>"
+            f"<td>{_labels(node.labels)}</td>"
+            f"<td>{linked}</td>"
+            f"<td>{_handoff_cell(node)}</td>"
+            "</tr>"
+        )
+    if not rows:
+        return (
+            '<tr><td colspan="6" class="muted">No pull requests in the loaded '
+            "window.</td></tr>"
+        )
+    return "".join(rows)
+
+
+def _focus_card(snapshot: LinkageSnapshot) -> str:
+    """Render the focused thread's latest canonical handoff, when one was loaded."""
+    if snapshot.focus is None:
+        return f"""<div class="prompt-card">
+  <h3>Canonical handoff</h3>
+  <p class="muted">{escape(snapshot.handoff_status.reason or "")}
+  Add <code>?issue=N</code> or <code>?pr=N</code> to load the latest
+  Canonical Thread Handoff for one thread.</p>
+</div>"""
+
+    kind, number = snapshot.focus
+    target = f"{kind} #{number}"
+    if not snapshot.handoff_status.loaded:
+        return f"""<div class="prompt-card">
+  <h3>Canonical handoff — {escape(target)}</h3>
+  <p class="muted">{_badge("unavailable", "badge-health-degraded")}
+  {escape(snapshot.handoff_status.reason or "handoff source did not run")}.
+  This is not evidence that the thread carries no handoff.</p>
+</div>"""
+
+    handoff = next(
+        (
+            node.handoff
+            for node in (snapshot.issues + snapshot.prs)
+            if node.kind == kind and node.number == number and node.handoff
+        ),
+        None,
+    )
+    if handoff is None:
+        return f"""<div class="prompt-card">
+  <h3>Canonical handoff — {escape(target)}</h3>
+  <p class="muted">Comments loaded; no Canonical Thread Handoff comment found on
+  this thread.</p>
+</div>"""
+
+    type_css = "badge-health-ok" if handoff.cth_type_known else "badge-health-degraded"
+    unknown_note = (
+        ""
+        if handoff.cth_type_known
+        else (
+            '<p class="muted">The comment\'s heading is not a declared CTH type, '
+            "so it is reported as unrecognized rather than republished.</p>"
+        )
+    )
+    return f"""<div class="prompt-card">
+  <h3>Canonical handoff — {escape(target)}</h3>
+  <p class="meta">{_badge(handoff.cth_type or "—", type_css)}
+  by <code>{escape(handoff.author or "unknown")}</code>
+  at <code>{escape(handoff.created_at or "unknown")}</code></p>
+  {unknown_note}
+  <table class="detail">
+    <tr><th>Status</th><td>{escape(handoff.status or "—")}</td></tr>
+    <tr><th>Next owner</th><td>{escape(handoff.next_owner or "—")}</td></tr>
+    <tr><th>Current blocker</th><td>{escape(handoff.current_blocker or "—")}</td></tr>
+    <tr><th>Decision</th><td>{escape(handoff.decision or "—")}</td></tr>
+    <tr><th>Next action</th><td>{escape(handoff.next_action or "—")}</td></tr>
+  </table>
+  <p class="muted">Full event history:
+  <a href="/api/v1/timeline?{escape(kind)}={number}"><code>/api/v1/timeline</code></a></p>
+</div>"""
+
+
+def _legend_card(snapshot: LinkageSnapshot) -> str:
+    items = "".join(
+        f"<li>{_badge(_EVIDENCE_LABEL[name], _EVIDENCE_CSS[name])} — "
+        f"{escape(EVIDENCE_DESCRIPTIONS[name])}</li>"
+        for name in EVIDENCE_ORDER
+    )
+    reveal_note = (
+        "Gitea deep links are shown because the "
+        "<code>GITEA_MCP_REVEAL_ENDPOINTS</code> admin opt-in is set."
+        if snapshot.deep_links_enabled
+        else (
+            "Gitea deep links are withheld. Set "
+            "<code>GITEA_MCP_REVEAL_ENDPOINTS=1</code> server-side to reveal "
+            "them; item numbers stay usable without them."
+        )
+    )
+    return f"""<div class="prompt-card">
+  <h3>How an edge was found</h3>
+  <ul class="reasons">{items}</ul>
+  <p class="muted">{reveal_note}</p>
+  <p class="muted">Read-only surface: no issue or PR editing, no review, and no merge.
+  JSON export: <a href="/api/v1/gitea/linkage"><code>/api/v1/gitea/linkage</code></a></p>
+</div>"""
+
+
+def render_linkage_page(snapshot: LinkageSnapshot) -> str:
+    """Render the full HTML page for the Gitea linkage console."""
+    if not snapshot.ok:
+        return render_page(
+            title="Gitea linkage",
+            body_html=f"""<h2>Gitea issue and PR linkage</h2>
+<p class="meta">Phase 3 read-only linkage console (#645).</p>
+{_error_card(snapshot)}
+{_scope_card(snapshot)}""",
+        )
+
+    body = f"""<h2>Gitea issue and PR linkage</h2>
+<p class="meta">Phase 3 read-only linkage console (#645). Gitea remains the source of
+truth; this page reads it and never writes to it.</p>
+{_scope_card(snapshot)}
+{_contested_card(snapshot)}
+
+<div class="prompt-card">
+  <h3>Issues → pull requests</h3>
+  <table class="registry">
+    <thead>
+      <tr>
+        <th>Issue</th><th>Title</th><th>State</th><th>Labels</th>
+        <th>Linked PRs</th><th>Latest handoff</th>
+      </tr>
+    </thead>
+    <tbody>{_issue_rows(snapshot)}</tbody>
+  </table>
+</div>
+
+<div class="prompt-card">
+  <h3>Pull requests → issues</h3>
+  <table class="registry">
+    <thead>
+      <tr>
+        <th>PR</th><th>Title</th><th>State</th><th>Labels</th>
+        <th>Linked issues</th><th>Latest handoff</th>
+      </tr>
+    </thead>
+    <tbody>{_pr_rows(snapshot)}</tbody>
+  </table>
+</div>
+
+{_focus_card(snapshot)}
+{_legend_card(snapshot)}
+"""
+    return render_page(title="Gitea linkage", body_html=body)

webui/nav.py

@@ -6,7 +6,8 @@ destination is a GET view or a Phase 1 placeholder. No mutation links.
 
 Nav groups follow the #631 Phase 1 information architecture: Health, Traffic,
 Runtime/Sessions, Projects, Inventory, Timeline, Policy (placeholder), and
-Insights (placeholder). Later-phase surfaces are declared as ``stub`` items and
+Insights (placeholder), joined by the Phase 3 Gitea linkage group (#645).
+Later-phase surfaces are declared as ``stub`` items and
 backed by ``STUB_PAGES`` so their nav links resolve to a graceful placeholder
 instead of a 404.
 """
@@ -60,6 +61,9 @@ NAV_GROUPS: tuple[NavGroup, ...] = (
     NavGroup("Timeline", (
         NavItem("/timeline", "Timeline", "stub"),
     )),
+    NavGroup("Gitea", (
+        NavItem("/gitea", "Issue/PR linkage"),
+    )),
     NavGroup("Policy", (
         NavItem("/policy", "Policy", "stub"),
         NavItem("/prompts", "Prompts"),

webui/queue_loader.py

@@ -211,6 +211,19 @@ def _pagination_from_pages(
     )
 
 
+_SUPPORTED_FETCH_STATES = ("open", "closed", "all")
+
+
+def _safe_state(state: str | None) -> str:
+    """Constrain a caller-supplied item state before it reaches a query string.
+
+    The value is interpolated into the Gitea URL, so an unrecognised state falls
+    back to ``open`` rather than being passed through.
+    """
+    text = (state or "open").strip().lower()
+    return text if text in _SUPPORTED_FETCH_STATES else "open"
+
+
 def _fetch_prs(
     host: str,
     org: str,
@@ -218,8 +231,15 @@ def _fetch_prs(
     auth: str,
     *,
     per_page: int = 50,
+    state: str = "open",
 ) -> tuple[list[dict], PaginationMeta]:
-    url = f"{repo_api_url(host, org, repo)}/pulls?state=open"
+    """Fetch PRs in *state* (``open``, ``closed``, or ``all``).
+
+    The queue dashboard only ever wants the open window, so ``open`` stays the
+    default. The linkage console (#645) widens it, because a landed issue↔PR
+    edge lives on a merged PR.
+    """
+    url = f"{repo_api_url(host, org, repo)}/pulls?state={_safe_state(state)}"
     all_raw: list[dict] = []
     pages_fetched = 0
     is_final = False
@@ -248,8 +268,13 @@ def _fetch_issues(
     auth: str,
     *,
     per_page: int = 50,
+    state: str = "open",
 ) -> tuple[list[dict], PaginationMeta]:
-    url = f"{repo_api_url(host, org, repo)}/issues?state=open&type=issues"
+    """Fetch issues in *state* (``open``, ``closed``, or ``all``); see :func:`_fetch_prs`."""
+    url = (
+        f"{repo_api_url(host, org, repo)}/issues"
+        f"?state={_safe_state(state)}&type=issues"
+    )
     all_raw: list[dict] = []
     page = 1
     pages_fetched = 0