fix: remove hardcoded service URLs, require ENV config

- Remove hardcoded default URLs (portainer, npm, ollama, etc.)
- All external service URLs now required via ENV vars
- Remove obsolete ai_client and ai_controller (core-ai proxy)
- Clean up health_controller obsolete core-ai references
- App fails fast at startup if required config missing

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

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

src/main.py

@@ -13,7 +13,6 @@ from src.controllers.infrastructure_controller import infrastructure_controller
 from src.controllers.tools_controller import tools_controller
 from src.controllers.health_controller import health_controller
 from src.controllers.static_controller import static_controller
-from src.controllers.ai_controller import router as ai_router
 from src.controllers.housekeeping_controller import housekeeping_controller
 from src.security import initialize_oidc
 
@@ -101,7 +100,6 @@ app.include_router(tools_controller.router)                    # /tools/*
 app.include_router(infrastructure_controller.router)           # /infrastructure/*
 app.include_router(housekeeping_controller.router)             # /housekeeping/*
 app.include_router(static_controller.router)                   # /static/*
-app.include_router(ai_router)                                  # /ai/*
 
 
 # Global exception handler