Remove ensure_room/ensure_tracking from Protocol - tests prove not needed

Tests with SimpleRoomStorage and SimpleTrackingStorage (without ensure_*)
show that add_bounty() and track_bounty() work fine without explicit
ensure methods - they create rooms/tracking internally.

This simplifies the Protocol to only essential methods.

core/ports.py

@@ -24,10 +24,6 @@ class RoomStorage(Protocol):
         """Save all data for a room."""
         ...
 
-    def ensure_room(self, room_id: int) -> RoomData:
-        """Ensure a room exists, creating it if necessary. Returns RoomData."""
-        ...
-
     def add_bounty(self, room_id: int, bounty: Bounty) -> None:
         """Add a new bounty to a room. Creates room if it doesn't exist."""
         ...
@@ -50,7 +46,6 @@ class TrackingStorage(Protocol):
     """Storage port for tracking data.
 
     Tracks which bounties a user is tracking in a specific room.
-    Use ensure_tracking() to create a new tracking entry before tracking bounties.
     """
 
     def load(self, room_id: int, user_id: int) -> TrackingData | None:
@@ -61,12 +56,8 @@ class TrackingStorage(Protocol):
         """Save tracking data."""
         ...
 
-    def ensure_tracking(self, room_id: int, user_id: int) -> TrackingData:
-        """Ensure tracking exists for user in room, creating if necessary. Returns TrackingData."""
-        ...
-
     def track_bounty(self, room_id: int, user_id: int, tracked: TrackedBounty) -> None:
-        """Add a bounty to a user's tracking list. Creates tracking if needed."""
+        """Add a bounty to a user's tracking list. Creates tracking entry if needed."""
         ...
 
     def untrack_bounty(self, room_id: int, user_id: int, bounty_id: int) -> None: