Remediate PR #861 findings F1-F9 and TestWorktreeStart failures (#860)

- Fix F1: Prepare recovery worktree detached at remote_head without git checkout -B to avoid exit 128 when branch is held by source worktree
- Fix F2: Pass recovery_sanctioned=True in bind_session_lock and assess_same_issue_lease_conflict
- Fix F3: Add SOURCE_RECOVER_DIRTY_ORPHANED to SANCTIONED_LOCK_SOURCES
- Fix F4: Stop after Phase 4 dirty apply when conflicts exist; do not finalize session binding
- Fix F5: Dynamically query competing live locks and workflow leases in MCP server
- Fix F6: Fail closed on recovery worktree resume when HEAD does not match expected remote_head
- Fix F7: Fail closed on remote HEAD observation failure rather than copying expected_remote_head pin
- Fix F8: Enforce foreign overwrite protection requiring same claimant or sanctioned reclaim
- Fix F9: Add real multi-worktree integration tests for prepare_recovery_worktree and lock rebind
- Fix TestWorktreeStart: Bypass session lock check for dry-run and review/pr-* branches in scripts/worktree-start

dirty_orphan_worktree_recovery.py

@@ -725,13 +725,14 @@ def prepare_recovery_worktree(
         )
         head = (probe.stdout or "").strip()
         if probe.returncode != 0 or head != remote_head:
-            # Allow dirty recovery worktree after prior partial apply.
             return {
-                "success": True,
+                "success": False,
                 "created": False,
                 "resumed": True,
                 "head": head,
-                "reasons": [],
+                "reasons": [
+                    f"resume recovery worktree HEAD '{head}' does not match expected remote HEAD '{remote_head}'"
+                ],
             }
         return {
             "success": True,
@@ -741,7 +742,8 @@ def prepare_recovery_worktree(
             "reasons": [],
         }
 
-    # Create detached-at-head worktree then force branch association carefully.
+    # Create detached-at-head worktree. Do not run git checkout -B because
+    # the source worktree holds the branch name (Git exit 128).
     add = git.run(
         [
             "git",
@@ -761,19 +763,6 @@ def prepare_recovery_worktree(
                 f"git worktree add failed: {(add.stderr or add.stdout or '').strip()}"
             ],
         }
-    # Create/update local branch pointer without moving source.
-    br = git.run(
-        ["git", "checkout", "-B", branch_name],
-        cwd=recovery_worktree_path,
-    )
-    if br.returncode != 0:
-        return {
-            "success": False,
-            "created": True,
-            "reasons": [
-                f"branch checkout failed: {(br.stderr or br.stdout or '').strip()}"
-            ],
-        }
     return {
         "success": True,
         "created": True,
@@ -965,6 +954,27 @@ def run_dirty_orphan_recovery(
     journal["source_still_present"] = os.path.isdir(source_worktree_path)
     save_journal(journal, journal_dir=journal_dir)
 
+    # #860 F4: Do NOT finalize session binding if conflicts remain.
+    if conflicts:
+        return {
+            "success": False,
+            "performed": True,
+            "outcome": CONFLICTS_PRESENT,
+            "reasons": [
+                "conflicts present: manual resolution required before session binding (fail closed)"
+            ],
+            "conflicts": list(conflicts),
+            "recovery_worktree_path": recovery_worktree_path,
+            "source_worktree_path": source_worktree_path,
+            "source_frozen": True,
+            "journal": journal,
+            "evidence": {
+                "written_paths": written,
+                "conflict_state_path": conflict_state_path,
+                "accepted_head": expected_remote_head,
+            },
+        }
+
     # Phase 5: bind session (optional for pure assessor tests).
     pid = session_pid if session_pid is not None else os.getpid()
     lock_record = build_recovery_lock_record(
@@ -992,7 +1002,9 @@ def run_dirty_orphan_recovery(
             except Exception:
                 prior_gen = None
             _ils.bind_session_lock(
-                lock_record, expected_generation=prior_gen
+                lock_record,
+                expected_generation=prior_gen,
+                recovery_sanctioned=True,
             )
         else:
             lock_writer(lock_record)
@@ -1013,13 +1025,12 @@ def run_dirty_orphan_recovery(
     journal["complete"] = True
     save_journal(journal, journal_dir=journal_dir)
 
-    outcome = CONFLICTS_PRESENT if conflicts else RECOVERY_COMPLETED
     return {
         "success": True,
         "performed": True,
-        "outcome": outcome,
+        "outcome": RECOVERY_COMPLETED,
         "reasons": [],
-        "conflicts": list(conflicts),
+        "conflicts": [],
         "recovery_worktree_path": recovery_worktree_path,
         "source_worktree_path": source_worktree_path,
         "source_frozen": True,