feat: implement /recover command for listing and recovering soft-deleted bounties

- Add recover_bounty method to BountyService (admin-only)
- Add cmd_recover handler for listing and recovering deleted bounties
- Register /recover command in bot.py
- Add /recover to bot command list

/recover - list all recoverable bounties (sorted by deleted_at desc)
/recover <id...> - recover specific bounty(ies)

Output formats:
List: [#1] Deleted bounty | 🗑️ Deleted 2 Apr 2026
Recover: ✅ Recovered bounty #1. or ⛔ Bounty #5 not found or not deleted.

Fixes #49

core/services.py

@@ -210,6 +210,33 @@ class BountyService:
         self._storage.update_bounty(room_id, bounty)
         return True
 
+    def recover_bounty(
+        self, room_id: int, bounty_id: int, user_id: int
+    ) -> tuple[bool, str]:
+        """Recover a soft-deleted bounty. Only admins can recover.
+
+        Returns (success, message) tuple.
+        """
+        if not self.is_admin(room_id, user_id):
+            raise PermissionError("Only admins can recover bounties.")
+
+        all_bounties = self._storage.list_all_bounties(room_id, include_deleted=True)
+        bounty = None
+        for b in all_bounties:
+            if b.id == bounty_id:
+                bounty = b
+                break
+
+        if not bounty:
+            return False, f"Bounty #{bounty_id} not found."
+
+        if bounty.deleted_at is None:
+            return False, f"Bounty #{bounty_id} is not deleted."
+
+        bounty.deleted_at = None
+        self._storage.update_bounty(room_id, bounty)
+        return True, f"Recovered bounty #{bounty_id}."
+
 
 class TrackingService:
     """Service for tracking bounty operations."""