chore(db): add decisions-orphan-tickets CLI (#887)

New `tooling/db/decision orphan-tickets` subcommand scans tickets with
a decision_ref that doesn't match any row in the decisions table.
Surfaces silently orphaned tickets from typo'd or renumbered D-IDs.
Makefile target: `make decisions-orphan-tickets`.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

tooling/db/decisions_sync.py

@@ -457,6 +457,35 @@ def show_decision(cfg, decision_id):
         conn.close()
 
 
+def orphan_tickets(cfg):
+    """List tickets whose decision_ref is set but does not match any decision in the DB."""
+    conn = get_connection(cfg)
+    try:
+        rows = conn.execute(
+            """SELECT t.id, t.title, t.decision_ref, t.status, t.team
+               FROM tickets t
+               WHERE t.decision_ref IS NOT NULL
+                 AND t.decision_ref != ''
+                 AND t.decision_ref NOT IN (SELECT id FROM decisions)
+               ORDER BY t.decision_ref, t.id""",
+        ).fetchall()
+
+        orphans = [dict(r) for r in rows]
+
+        return {
+            "ok": True,
+            "count": len(orphans),
+            "orphans": orphans,
+            "summary": (
+                f"{len(orphans)} orphan ticket(s) found"
+                if orphans
+                else "No orphan tickets — all decision_ref values are valid"
+            ),
+        }
+    finally:
+        conn.close()
+
+
 def check_dupes(cfg):
     """Check for duplicate decision IDs across all markdown files."""
     # Pre-existing collisions too deeply embedded to renumber (139+ references).
@@ -508,6 +537,7 @@ Usage:
   decisions_sync.py next [D|Q|R]                Show next available ID (all prefixes or one)
   decisions_sync.py claim <D|Q|R> <domain> [title]  Claim next ID and insert placeholder
   decisions_sync.py check-dupes                 Check for duplicate IDs across markdown files
+  decisions_sync.py orphan-tickets              List tickets with invalid/missing decision_ref
   decisions_sync.py --help                      Show this help message
 
 ID claiming workflow:
@@ -554,6 +584,8 @@ def main():
             result = claim_id(cfg, prefix, domain, title)
     elif cmd == "check-dupes":
         result = check_dupes(cfg)
+    elif cmd == "orphan-tickets":
+        result = orphan_tickets(cfg)
     else:
         result = {"ok": False, "error": f"Unknown command: {cmd}. Use --help for usage."}