Enforce issue-write tool gates to match task capability resolver (Issue #69)

Extract TASK_CAPABILITY_MAP into task_capability_map.py as the single source
of truth shared by gitea_resolve_task_capability and issue-mutating tools.
Gate gitea_create_issue, gitea_close_issue, gitea_mark_issue, and
gitea_set_issue_labels with structured #142 permission reports. Add regression
tests proving resolver-denied tasks fail closed at the raw tool layer.

Implements mcp-control-plane #69.

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

gitea_mcp_server.py

@@ -257,6 +257,7 @@ import gitea_config  # noqa: E402
 import capability_stop_terminal  # noqa: E402
 import issue_duplicate_gate  # noqa: E402
 import role_session_router  # noqa: E402
+import task_capability_map  # noqa: E402
 
 
 # Fail-closed exact-issue-lock file (#204): written by gitea_lock_issue,
@@ -555,6 +556,12 @@ def gitea_create_issue(
             "number": None,
             "reasons": block_reasons,
         }
+    blocked = _profile_permission_block(
+        task_capability_map.required_permission("create_issue"),
+        number=None,
+    )
+    if blocked:
+        return blocked
     verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
@@ -2494,6 +2501,10 @@ def gitea_close_issue(
     Returns:
         dict with 'success' boolean and 'message'.
     """
+    blocked = _profile_permission_block(
+        task_capability_map.required_permission("close_issue"))
+    if blocked:
+        return blocked
     verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
@@ -2698,6 +2709,25 @@ def _profile_operation_gate(op: str) -> list[str]:
     return [f"profile is not allowed to {op}"]
 
 
+def _profile_permission_block(required_operation: str, **extra_fields) -> dict | None:
+    """Structured permission denial for gated tools (#69, #142).
+
+    Returns a block dict when the active profile forbids *required_operation*,
+    or ``None`` when the gate passes. Never performs network I/O.
+    """
+    reasons = _profile_operation_gate(required_operation)
+    if not reasons:
+        return None
+    blocked = {
+        "success": False,
+        "performed": False,
+        "reasons": reasons,
+        "permission_report": _permission_block_report(required_operation),
+    }
+    blocked.update(extra_fields)
+    return blocked
+
+
 @mcp.tool()
 def gitea_list_issue_comments(
     issue_number: int,
@@ -3882,6 +3912,10 @@ def gitea_mark_issue(
     if action not in ("start", "done"):
         raise ValueError(f"action must be 'start' or 'done', got '{action}'")
 
+    blocked = _profile_permission_block(
+        task_capability_map.required_permission("mark_issue"))
+    if blocked:
+        return blocked
     verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
@@ -4005,6 +4039,10 @@ def gitea_set_issue_labels(
     Returns:
         list of all labels currently applied to the issue.
     """
+    blocked = _profile_permission_block(
+        task_capability_map.required_permission("set_issue_labels"))
+    if blocked:
+        return blocked
     verify_preflight_purity(remote)
     h, o, r = _resolve(remote, host, org, repo)
     auth = _auth(h)
@@ -4199,86 +4237,13 @@ def gitea_resolve_task_capability(
         remote: Known remote instance name.
         host: Optional override for the Gitea host.
     """
-    TASK_MAP = {
-        "create_issue": {
-            "permission": "gitea.issue.create",
-            "role": "author",
-        },
-        "comment_issue": {
-            "permission": "gitea.issue.comment",
-            "role": "author",
-        },
-        "close_issue": {
-            "permission": "gitea.issue.close",
-            "role": "author",
-        },
-        "claim_issue": {
-            "permission": "gitea.issue.comment",
-            "role": "author",
-        },
-        "mark_issue": {
-            "permission": "gitea.issue.comment",
-            "role": "author",
-        },
-        "create_branch": {
-            "permission": "gitea.branch.create",
-            "role": "author",
-        },
-        "push_branch": {
-            "permission": "gitea.branch.push",
-            "role": "author",
-        },
-        "create_pr": {
-            "permission": "gitea.pr.create",
-            "role": "author",
-        },
-        "comment_pr": {
-            "permission": "gitea.pr.comment",
-            "role": "author",
-        },
-        # PR closure is a first-class capability (#216): distinct from
-        # comment_pr (gitea.pr.comment) and from ordinary PR edits, which
-        # need no dedicated capability. gitea_edit_pr(state='closed') is
-        # gated on the same operation, so no edit-path fallback exists.
-        "close_pr": {
-            "permission": "gitea.pr.close",
-            "role": "author",
-        },
-        "address_pr_change_requests": {
-            "permission": "gitea.branch.push",
-            "role": "author",
-        },
-        "review_pr": {
-            "permission": "gitea.pr.review",
-            "role": "reviewer",
-        },
-        "merge_pr": {
-            "permission": "gitea.pr.merge",
-            "role": "reviewer",
-        },
-        "blind_pr_queue_review": {
-            "permission": "gitea.pr.review",
-            "role": "reviewer",
-        },
-        "request_changes_pr": {
-            "permission": "gitea.pr.request_changes",
-            "role": "reviewer",
-        },
-        "approve_pr": {
-            "permission": "gitea.pr.approve",
-            "role": "reviewer",
-        },
-        "delete_branch": {
-            "permission": "gitea.branch.delete",
-            "role": "author",
-        },
-    }
+    TASK_MAP = task_capability_map.TASK_CAPABILITY_MAP
 
     if task not in TASK_MAP:
         raise ValueError(f"Unknown task/action: '{task}' (fail closed)")
 
-    required_permission = TASK_MAP[task]["permission"]
-    required_role = TASK_MAP[task]["role"]
+    required_permission = task_capability_map.required_permission(task)
+    required_role = task_capability_map.required_role(task)
 
     record_preflight_check("capability", required_role)