refactor: remove Ollama integration and unused AI configuration

- Remove src/models/ollama_client.py, embeddings.py, embeddings_ollama.py
- Remove model aliases and AI config from settings (both config.py files)
- Update health endpoints to only check database connectivity
- Update tests to reflect database-only health checks
- Update README, .env.example, and OIDC docstrings

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/main.py

@@ -10,7 +10,6 @@ from src.shared.config import get_settings
 from src.shared.logging import setup_logging, get_logger
 from src.shared.database import get_database
 from src.shared.security import initialize_oidc
-from src.models.ollama_client import get_ollama_client, close_ollama_client
 
 # Import domain controllers
 from src.domains.health import health_controller
@@ -42,17 +41,8 @@ async def lifespan(app: FastAPI):
     logger.info(f"Starting {settings.app_name} v{settings.app_version}")
     logger.info(f"Debug mode: {settings.debug}")
     logger.info(f"Log level: {settings.log_level}")
-    logger.info(f"Ollama URL: {settings.ollama_base_url}")
     logger.info("=" * 60)
 
-    # Check Ollama connectivity
-    ollama_client = get_ollama_client()
-    ollama_healthy = await ollama_client.health_check()
-    if ollama_healthy:
-        logger.info("Ollama connection successful")
-    else:
-        logger.warning("Ollama connection failed - AI features may not work")
-
     # Check database connectivity
     database = get_database()
     db_healthy = await database.health_check()
@@ -68,7 +58,6 @@ async def lifespan(app: FastAPI):
 
     # Shutdown
     logger.info("Shutting down application")
-    await close_ollama_client()
     await database.close()