Add OpenAPI generator

README.md

@@ -31,6 +31,8 @@ MailHog listens on `http://localhost:8025`.
 Local CORS allows `http://localhost:5173` by default for the future Vue frontend.
 Multipart uploads currently accept report images and videos up to the app body
 limit configured in `config.json`.
+Swagger UI is available at `http://localhost:5555/api/v1/docs` after the app
+has been built.
 
 Local seeded admin:
 
@@ -71,6 +73,19 @@ discoverable by CMake. The default build uses CPM.cmake and downloads Drogon
 - `docs/DATABASE_SCHEMA.md`: schema overview.
 - `docs/ARCHITECTURE.md`: backend structure.
 
+## OpenAPI
+
+The OpenAPI spec is generated from Drogon controller route macros, not written
+as a static Swagger file.
+
+```bash
+cmake --build build --target openapi
+python3 -m json.tool build/openapi/visione.openapi.json >/dev/null
+```
+
+The app serves the generated JSON at `/api/v1/openapi.json` and Swagger UI at
+`/api/v1/docs`.
+
 ## Development Workflow
 
 1. Keep MySQL running with `docker compose up -d`.
@@ -89,6 +104,8 @@ cmake --build build
 ctest --test-dir build --output-on-failure
 ```
 
+8. After each completed and verified feature, create a short commit.
+
 The `RequestLogger` plugin logs every response as method, path, status and
 client address.