feat: non-destructive lock recovery for pushed branches (Closes #440)

Adds structured issue-branch ownership parsing, wires it into lock adoption
and gitea_lock_issue validation, documents the restart recovery workflow, and
adds regression tests for adoption, durable create_pr resolution, and open-PR
blocking without remote branch deletion.

Built on keyed persistent lock store and own-branch adoption (#443 / #442).

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

gitea_mcp_server.py

@@ -540,6 +540,7 @@ import agent_temp_artifacts
 import issue_lock_worktree  # noqa: E402
 import issue_lock_store  # noqa: E402
 import issue_lock_adoption  # noqa: E402
+import issue_branch_ownership  # noqa: E402
 import already_landed_reconcile  # noqa: E402
 import author_mutation_worktree  # noqa: E402
 import issue_claim_heartbeat  # noqa: E402
@@ -1171,11 +1172,11 @@ def gitea_lock_issue(
         worktree_path: Author scratch-clone path to validate (defaults to
             GITEA_AUTHOR_WORKTREE or the MCP server project root).
     """
-    # 1. Enforce branch name includes issue number
-    expected_pattern = f"issue-{issue_number}"
-    if expected_pattern not in branch_name:
+    # 1. Enforce canonical issue branch ownership (#440)
+    if not issue_branch_ownership.branch_belongs_to_issue(branch_name, issue_number):
         raise ValueError(
-            f"Branch name '{branch_name}' must contain locked issue pattern '{expected_pattern}' (fail closed)"
+            f"Branch name '{branch_name}' must match "
+            f"(fix|feat|docs|chore)/issue-{issue_number}-<desc> (fail closed)"
         )
 
     blocked = _profile_permission_block(
@@ -1226,7 +1227,7 @@ def gitea_lock_issue(
         pr_title = pr.get("title", "")
         pr_body = pr.get("body", "")
 
-        if expected_pattern in pr_head:
+        if issue_branch_ownership.branch_belongs_to_issue(pr_head, issue_number):
             raise ValueError(
                 f"Issue #{issue_number} is already tied to an open PR (PR #{pr.get('number')}, branch '{pr_head}') (fail closed)"
             )