docs(architecture): add ADR for HA and rolling-restart MCP architecture (Closes #668)

Stale-runtime and runtime-mode mutation refusals previously shared the
permission-denial channel, so permission_report claimed a missing op the
active profile already held and recommended gitea_activate_profile.
Typed blocker_kind payloads report reconnect-only recovery for staleness,
omit permission_report for non-permission gates, and fail closed when a
permission_report would invent a missing permission the profile holds.

docs/architecture/mcp-ha-rolling-restart.md

@@ -0,0 +1,167 @@
+# ADR: High-availability and rolling-restart architecture for Gitea MCP control plane
+
+- **Status:** Proposed (Design ADR under [#668](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/668))
+- **Date:** 2026-07-25
+- **Tracking Issue:** [#668](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/668)
+- **Policy Version:** `mcp-ha-rolling-restart/v1`
+- **Related:**
+  - Parent: [#655](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/655) — Governed MCP restart coordination and zero-disruption recovery
+  - Governance Policy: [#656](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/656) / `docs/architecture/mcp-restart-governance.md`
+  - Control-Plane DB Substrate: [#613](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/613) / `docs/architecture/control-plane-db-substrate.md`
+  - Runtime Policy: [#615](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/615) / `docs/architecture/mcp-stable-control-runtime-policy-adr.md`
+  - Product Vision: [#652](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/652) (Phase 5 Maturity)
+  - Delivery Roadmap: [#653](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/653)
+
+---
+
+## 1. Context & Problem Statement
+
+The Gitea MCP server operates as the authoritative **control plane** for managing issues, Pull Requests, code mutations, formal reviews, and workflow reconciliations. Under single-process governance ([#656](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/656)), process restarts are strictly controlled using pre-flight checks, drain phases, and operator approvals.
+
+However, a single-instance control plane inherently presents fundamental constraints:
+
+1. **Downtime during updates:** Even a perfectly executed single-process drain requires a window where incoming client requests must be paused or rejected while the server binary or python environment reloads.
+2. **Single point of failure:** Infrastructure issues, process crashes, or unhandled host-level terminations immediately disconnect active LLM sessions and leave transient workflows incomplete.
+3. **Multi-agent concurrency bottlenecks:** High volumes of concurrent multi-LLM tasks put all lock management, lease allocation, and Gitea API interactions through a single process event loop.
+
+To achieve true zero-disruption operation and seamless rolling deployments without stopping active work, the system requires a high-availability (HA), multi-instance MCP architecture.
+
+---
+
+## 2. Architectural Principles & Non-Goals
+
+### 2.1 Core Architectural Principles
+* **Gitea as Canonical Work SoT:** Gitea remains the ultimate System of Record (SoT) for issue states, pull requests, labels, and audit comments. The MCP control plane does not duplicate domain entities.
+* **Control-Plane DB as Multi-Instance State Substrate:** The control-plane SQLite/durable database ([#613](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/613)) acts as the single source of truth for workflow leases, session tokens, assignment records, and lock fences across all MCP nodes.
+* **Stateless Worker Nodes:** MCP role server processes (`gitea-author`, `gitea-reviewer`, `gitea-merger`, `gitea-reconciler`, `gitea-controller`) maintain no unique in-memory state; any node can handle any request given a valid session resume token.
+* **Fail-Closed Split-Brain Defense:** In any network partition or quorum loss scenario, nodes must fail closed rather than risk double-mutations or conflicting Gitea states.
+
+### 2.2 Non-Goals
+* **Replacing Gitea:** We do not replace Gitea issue/PR tracking with an independent database.
+* **Immediate Multi-Node Cluster Execution in v1:** This ADR defines the target architecture and phased roadmap; immediate implementation occurs incrementally post-[#655] v1.
+
+---
+
+## 3. High-Availability & Rolling-Restart Architecture
+
+### 3.1 Architecture Overview
+
+```
+                        +----------------------------+
+                        | LLM Clients / IDE Sessions |
+                        +--------------+-------------+
+                                       |
+                                       v
+                        +----------------------------+
+                        |    HA Proxy / Router       |
+                        | (Health-based & Affinity)  |
+                        +------+--------------+------+
+                               |              |
+                +--------------+              +--------------+
+                v                                            v
+     +--------------------+                        +--------------------+
+     | MCP Instance Node A|                        | MCP Instance Node B|
+     | (Version N)        |                        | (Version N+1)      |
+     +---------+----------+                        +---------+----------+
+               |                                             |
+               +----------------------+----------------------+
+                                      |
+                                      v
+                        +----------------------------+
+                        |  Control-Plane DB Substrate|
+                        |  (Shared Lease & Locks)    |
+                        +--------------+-------------+
+                                       |
+                                       v
+                        +----------------------------+
+                        |        Gitea API           |
+                        +----------------------------+
+```
+
+---
+
+### 3.2 Key System Components
+
+#### A. Multiple MCP Instance Cohorts
+* The control plane runs across $N \ge 2$ redundant process nodes.
+* Dual-namespace deployment allows running the old version (Node A) alongside a updated version (Node B) during rolling upgrades.
+
+#### B. Shared Durable Session Storage & Resume Tokens
+* Session context, preflight verification proofs, and capability resolution states are stored in the shared control-plane database.
+* Client requests carry an explicit `session_id` and `resume_token`. If an MCP instance restarts or a request routes to a different instance, the target node validates the token against the database without requiring full session re-initialization.
+
+#### C. Shared Lease Authority & Fencing Counters
+* Workflow leases (`gitea_allocate_next_work`, `gitea_adopt_workflow_lease`) use monotonic fencing tokens (`lease_generation_id`).
+* When Node B acquires or renews a lease, it increments the generation counter. Any delayed or out-of-order write attempt from Node A using an older generation token is rejected by database constraints.
+
+#### D. Leader Election & Coordinated Drain
+* Node clusters elect a primary coordinator node for administrative background tasks (such as stale lease cleanup or incident Watchdogs).
+* During a rolling deployment:
+  1. Node B (new version) is launched and registers as healthy.
+  2. Router directs new session creations to Node B.
+  3. Node A enters `MAINTENANCE_DRAIN` status ([#659](https://gitea.prgs.cc/Scaled-Tech-Consulting/Gitea-Tools/issues/659)), completing in-flight mutations while refusing new tasks.
+  4. Once all active sessions migrate or complete, Node A shuts down cleanly.
+
+#### E. Idempotent Mutations & Failover Safety
+* All state-changing tool executions (PR creation, review submission, merge operations, label changes) carry a deterministic `idempotency_key`.
+* If a network connection flaps or a node fails mid-mutation, the re-issued request with the same `idempotency_key` is recognized by the control-plane substrate, returning the existing recorded result without repeating side effects on Gitea.
+
+#### F. Schema Version Compatibility
+* Database migrations follow non-breaking additive patterns.
+* During rolling upgrades where Node A (Version $N$) and Node B (Version $N+1$) run concurrently, both versions operate against the shared schema without structural conflicts.
+
+---
+
+## 4. Split-Brain & Failure Behavior
+
+### 4.1 Split-Brain Risk Scenarios & Mitigation
+
+| Scenario | Risk | Mitigation Strategy |
+|---|---|---|
+| **Network Partition between Nodes** | Both Node A and Node B attempt to process operations for the same issue/PR. | **Generation Fencing:** Lease renewal requires updating the DB generation counter. The node isolated from the DB fails closed immediately. |
+| **Stale Node Recovery** | Node A recovers after a long pause and executes a queued mutation. | **Lease Expiry & TTL Fencing:** Transactions verify that `expires_at > NOW()` within the atomic SQLite transaction boundaries. |
+| **Database Connection Loss** | Node loses access to shared control-plane DB substrate. | **Strict Fail-Closed:** The node immediately marks all task capabilities as `blocked` and rejects mutation tools until DB connectivity is re-established. |
+
+---
+
+## 5. Phased Implementation Milestones
+
+```mermaid
+flowchart TD
+    M1[Milestone 1: Shared Control-Plane DB Schema & Resume Tokens] --> M2[Milestone 2: Idempotent Mutation Layer]
+    M2 --> M3[Milestone 3: Health Routing & Standby Failover]
+    M3 --> M4[Milestone 4: Active-Active Rolling Deployment & Auto-Drain]
+```
+
+### Milestone 1: Shared Control-Plane DB Schema & Resume Tokens (Post-#655)
+* Extend [#613] Control-Plane DB schema to store multi-instance node heartbeat records and session resume tokens.
+* Enable session lookup across instances via `session_id`.
+
+### Milestone 2: Idempotent Mutation Layer & Lease Fencing
+* Add mandatory `idempotency_key` tracking to all Gitea mutation tools.
+* Implement monotonic lease fencing counters in `gitea_allocate_next_work` and `gitea_adopt_workflow_lease`.
+
+### Milestone 3: Health-Based Routing & Active-Passive Standby
+* Introduce lightweight proxy/router capable of checking node health endpoints.
+* Implement active-standby failover where standby node automatically assumes work if active node fails health checks.
+
+### Milestone 4: Active-Active Horizontal Deployment & Rolling Upgrade Automation
+* Enable true active-active multi-instance execution.
+* Integrate automated zero-downtime rolling upgrades coordinated with `gitea_request_mcp_restart` maintenance drain.
+
+---
+
+## 6. Observability & Audit Requirements
+
+High-availability control plane operations must expose clear telemetry and audit trails:
+
+* **Node Registry Telemetry:** Active nodes, version numbers, uptime, and heartbeat timestamps reported via `gitea_get_runtime_context`.
+* **Lease Fencing Metrics:** Tracking lease acquire latency, fence rejection counts, and lease handoff durations.
+* **Failover & Re-route Audit Logs:** Durable logging of session migrations between nodes, drain initiation, and process retirement events.
+
+---
+
+## 7. Tradeoffs & Accepted Risks
+
+* **Increased Architectural Complexity:** Moving from a single process to a multi-instance control plane requires robust DB locking, proxy routing, and migration governance.
+* **Database Dependency:** The control-plane database substrate becomes a critical shared dependency for multi-node deployments. High availability for the underlying SQLite file system / DB must be guaranteed.

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 {
-                "success": False,
-                "performed": False,
-                "pr_number": pr_number,
-                "requested_state": "closed",
-                "required_permission": "gitea.pr.close",
-                "reasons": gate_reasons,
-                "permission_report": _permission_block_report("gitea.pr.close"),
-            }
+            return _build_operation_gate_refusal(
+                "gitea.pr.close",
+                gate_reasons,
+                pr_number=pr_number,
+                requested_state="closed",
+                required_permission="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)
-    if stale_reasons:
-        return stale_reasons
-    runtime_reasons = _runtime_mode_block(op)
-    if runtime_reasons:
-        return runtime_reasons
+    reasons: list[str] = []
+    reasons.extend(_master_parity_block(op))
+    reasons.extend(_runtime_mode_block(op))
     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)"]
-    if op_reason == "forbidden":
-        return [f"profile forbids '{op}'"]
-    if op_reason == "invalid-forbidden-entry":
-        return ["profile has an unrecognized forbidden operation entry (fail closed)"]
-    return [f"profile is not allowed to {op}"]
+        reasons.append(
+            "profile has no configured allowed operations (fail closed)"
+        )
+    elif op_reason == "forbidden":
+        reasons.append(f"profile forbids '{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 = {
-            "success": False,
-            "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
+        return _build_operation_gate_refusal(
+            required_operation, reasons, **extra_fields
+        )
 
     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 {
-            "success": False,
-            "acquired": False,
-            "reasons": read_block,
-            "permission_report": _permission_block_report("gitea.read"),
-        }
+        return _build_operation_gate_refusal(
+            "gitea.read", read_block, acquired=False
+        )
     comment_block = _profile_operation_gate("gitea.pr.comment")
     if comment_block:
-        return {
-            "success": False,
-            "acquired": False,
-            "reasons": comment_block,
-            "permission_report": _permission_block_report("gitea.pr.comment"),
-        }
+        return _build_operation_gate_refusal(
+            "gitea.pr.comment", comment_block, acquired=False
+        )
 
     # 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 {
-            "success": False,
-            "acquired": False,
-            "reasons": read_block,
-            "permission_report": _permission_block_report("gitea.read"),
-        }
+        return _build_operation_gate_refusal(
+            "gitea.read", read_block, acquired=False
+        )
     comment_block = _profile_operation_gate("gitea.pr.comment")
     if comment_block:
-        return {
-            "success": False,
-            "acquired": False,
-            "reasons": comment_block,
-            "permission_report": _permission_block_report("gitea.pr.comment"),
-        }
+        return _build_operation_gate_refusal(
+            "gitea.pr.comment", comment_block, acquired=False
+        )
     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 {
-            "success": False,
-            "performed": False,
-            "mutation_allowed": False,
-            "reasons": push_block,
-            "permission_report": _permission_block_report("gitea.branch.push"),
-            "role_kind": role,
-        }
+        return _build_operation_gate_refusal(
+            "gitea.branch.push",
+            push_block,
+            mutation_allowed=False,
+            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()