Restructure FAST API app and load configuration into app

mapping_provider/__init__.py

-"""Initializes the FastAPI application."""
-import os
+"""Create a FastAPI application for the mapping provider."""
 
 from fastapi import FastAPI
 
-from mapping_provider import config
 from mapping_provider.api.common import router as version_router
-
+from mapping_provider.api.network_graph import router as graph_router
 
 def create_app() -> FastAPI:
     """Create a FastAPI application."""
@@ -14,9 +12,11 @@ def create_app() -> FastAPI:
         description="Mapping provider endpoints for GÉANT maps",
     )
 
-    config_file = os.environ.get("CONFIG_FILE_NAME", "config.json")
-    with config_file.open() as f:
-        app.state.config = config.load(f)
+    # Force configuration to be loaded at startup to avoid issues with missing config
+    from mapping_provider.dependencies import load_config
+    _ = load_config()
 
     app.include_router(version_router)
-    return app
+    app.include_router(graph_router)
+
+    return app
\ No newline at end of file

mapping_provider/dependencies.py

+"""FastAPI project dependencies."""
+
+import os
+from functools import lru_cache
+from typing import Annotated
+
+from fastapi import Depends
+from mapping_provider import config
+
+
+@lru_cache()
+def load_config() -> dict:
+    """Load and cache the application configuration."""
+    config_file = os.environ.get("CONFIG_FILE_NAME", "config.json")
+    with open(config_file) as f:
+        return config.load(f)
+
+
+# Dependency for injecting config into routes/services
+config_dep = Annotated[dict, Depends(load_config)]
\ No newline at end of file

mapping_provider/main.py

-"""The main module that runs the application."""
-
-from mapping_provider import create_app
-
-app = create_app()
-