fix(author): bootstrap recovery for dirty orphaned issue worktrees (#860)

Add an explicit recovery operation for same-claimant dirty registered
worktrees under malformed PID-less durable locks, with crash-safe journals,
dirty byte preservation, path-level conflict detection, and live session
binding. PID-less locks are never treated as live merely because expiry is
absent.

Closes #860

Co-Authored-By: Grok 4.5 (xAI) <[email protected]>

issue_lock_store.py

@@ -380,7 +380,16 @@ def assess_lock_freshness(
     pid = lock_data.get("session_pid")
     if pid is None:
         pid = lock_data.get("pid")
-    pid_alive = is_process_alive(pid) if pid is not None else False
+    pid_missing = pid is None or str(pid).strip() == ""
+    try:
+        pid_int = int(pid) if not pid_missing else None
+        if pid_int is not None and pid_int <= 0:
+            pid_missing = True
+            pid_int = None
+    except (TypeError, ValueError):
+        pid_missing = True
+        pid_int = None
+    pid_alive = is_process_alive(pid_int) if pid_int is not None else False
 
     if expires_at and expires_at <= current:
         return {
@@ -389,15 +398,36 @@ def assess_lock_freshness(
             "stale": True,
             "reason": f"lease expired at {expires_at.isoformat()}",
             "pid_alive": pid_alive,
+            "pid_missing": pid_missing,
         }
 
-    if pid is not None and not pid_alive:
+    # #860: a PID-less lock must never be considered live merely because
+    # expiration / heartbeat fields are absent. Missing PID is insufficient
+    # evidence of a live owner; treat as malformed/stale so recovery routes
+    # can evaluate corroborating pins instead of blocking on a false live flag.
+    if pid_missing:
+        return {
+            "status": "malformed",
+            "live": False,
+            "stale": True,
+            "reason": (
+                "lock has no usable session pid; cannot prove live ownership "
+                "(PID-less locks are never live by missing expiry alone)"
+            ),
+            "pid_alive": False,
+            "pid_missing": True,
+            "heartbeat_at": heartbeat_at.isoformat() if heartbeat_at else None,
+            "expires_at": expires_at.isoformat() if expires_at else None,
+        }
+
+    if pid_int is not None and not pid_alive:
         return {
             "status": "stale",
             "live": False,
             "stale": True,
-            "reason": f"owner pid {pid} is not alive",
+            "reason": f"owner pid {pid_int} is not alive",
             "pid_alive": False,
+            "pid_missing": False,
         }
 
     return {
@@ -406,6 +436,7 @@ def assess_lock_freshness(
         "stale": False,
         "reason": "lock heartbeat and lease are fresh",
         "pid_alive": pid_alive,
+        "pid_missing": False,
         "heartbeat_at": heartbeat_at.isoformat() if heartbeat_at else None,
         "expires_at": expires_at.isoformat() if expires_at else None,
     }