feat: use ${OLLAMA_CLOUD_API_KEY} from shared secrets

Replace hardcoded API key with env var placeholder.
Key now loaded from .common/secrets/interns.env via meeting-room runner.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

config/config.yaml

@@ -9,7 +9,7 @@ providers:
     api_key: ${MEETING_ROOM_ROUTERAI_API_KEY}
     base_url: ${MEETING_ROOM_ROUTERAI_BASE_URL}
   ollama_cloud:
-    api_key: 02a8f6e9f9744088885982ac645f1ce1.HB1MFh4AlTpyic9oJGxQjNuA
+    api_key: ${OLLAMA_CLOUD_API_KEY}
     base_url: https://ollama.com/v1
 
 roles: