Move API docs to conventional paths: /docs, /redoc, /openapi.json

Users expect Swagger at /docs; the app had mounted them under /api/*.
Also normalize user-facing product name to "SHONAR" in the app title and
root route (Python package stays shonar), and regenerate the shared
OpenAPI contract.

README.md

@@ -34,8 +34,9 @@ cp .env.example .env
 docker compose up -d --build
 ```
 
-Then open `http://localhost:8000/api/docs` for the interactive API docs and
-point the Android app at your server URL.
+Then open `http://localhost:8000/docs` for the interactive API docs and
+point the Android app at your server URL. (ReDoc at `/redoc`, raw schema at
+`/openapi.json`.)
 
 The default compose stack is: API + worker + PostgreSQL + Redis, with audio
 stored on the local filesystem. No paid cloud service is required.
@@ -84,7 +85,7 @@ you always know if your audio or text leaves your machine.
 ## Documentation
 
 - [docs/self-hosting.md](docs/self-hosting.md) — deployment, HTTPS, backups
-- [docs/api.md](docs/api.md) — API overview (OpenAPI at `/api/docs`)
+- [docs/api.md](docs/api.md) — API overview (OpenAPI at `/openapi.json`)
 - [docs/security.md](docs/security.md) — security model and honest limits
 - [docs/architecture.md](docs/architecture.md) — system design
 - [docs/recording-consent.md](docs/recording-consent.md) — legal notice