test(mcp): import resolve_bearer at module level

CI fix for aef5009: test_resolve_bearer_none_for_invalid referenced
resolve_bearer but the import lived inside an earlier test only. Hoist it
to the module import. Production code unaffected (1 failed / 284 passed).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_mcp_auth.py

@@ -3,7 +3,7 @@ from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
 
-from fabledassistant.mcp.auth import resolve_bearer_to_user_id
+from fabledassistant.mcp.auth import resolve_bearer, resolve_bearer_to_user_id
 
 
 @pytest.mark.asyncio
@@ -55,7 +55,6 @@ async def test_resolve_bearer_calls_lookup_with_stripped_token():
 
 @pytest.mark.asyncio
 async def test_resolve_bearer_returns_user_id_and_scope():
-    from fabledassistant.mcp.auth import resolve_bearer
     fake_key = MagicMock()
     fake_key.user_id = 9
     fake_key.scope = "read"