Summary

• Handle URL-remapped IDs in api_get_status so that remote/federated posts can be looked up via GET /api/v1/statuses/:id
• Moves reblog ID remapping earlier in the flow and adds a mastodon_api_status_by_url filter path for posts that map to remote URLs
• Returns 404 if the remote lookup yields no result

Test plan

• Fetch a local status by ID and verify it still works as before
• Fetch a remote/federated status by its remapped ID and verify it returns the correct status
• Fetch a non-existent ID and verify a 404 is returned