feat: register contract-driven API routes

app/main.py

@@ -6,7 +6,9 @@ from fastapi import FastAPI
 
 from app.api.errors import unhandled_exception_handler
 from app.api.middleware import RequestContextMiddleware
+from app.api.registry import HandlerRegistry, register_contract_routes
 from app.config import Settings, get_settings
+from app.contracts.model import Snapshot
 from app.lifespan import DatabaseFactory, create_lifespan, default_database_factory
 from app.logging import configure_logging
 from app.observability.health import router as health_router
@@ -15,6 +17,7 @@ from app.observability.health import router as health_router
 def create_app(
     settings: Settings | None = None,
     database_factory: DatabaseFactory = default_database_factory,
+    handlers: HandlerRegistry | None = None,
 ) -> FastAPI:
     """Create an isolated application instance with explicit resource factories."""
 
@@ -28,6 +31,14 @@ def create_app(
     app.add_middleware(RequestContextMiddleware, header_name=resolved.request_id_header)
     app.add_exception_handler(Exception, unhandled_exception_handler)
     app.include_router(health_router)
+    if resolved.contract_snapshot is not None:
+        snapshot = Snapshot.model_validate_json(resolved.contract_snapshot.read_bytes())
+        register_contract_routes(
+            app,
+            snapshot,
+            handlers or HandlerRegistry(),
+            resolved.contract_fallback,
+        )
     return app