feat(topology): add snapshot query logic, API route, and Flask app entry

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

topology_api/app.py

@@ -0,0 +1,20 @@
+# topology_api/app.py
+from flask import Flask
+from topology_api.config import API_HOST, API_PORT, API_DEBUG
+from topology_api.routes.snapshot import snapshot_bp
+
+
+def create_app():
+    app = Flask(__name__)
+    app.register_blueprint(snapshot_bp)
+
+    @app.route("/health")
+    def health():
+        return {"status": "ok"}
+
+    return app
+
+
+if __name__ == "__main__":
+    app = create_app()
+    app.run(host=API_HOST, port=API_PORT, debug=API_DEBUG)