feat: complete release readiness work

- consolidate API ownership and remove dead vendor code

- add Stripe billing, learning paths, and public CV hardening

- add migration, recovery, security, audit, and browser gates

docs/technical/logging.md

@@ -42,4 +42,14 @@ Include:
 - Operation.
 - User context where safe.
 - Error details.
-- Correlation IDs.
+- Correlation IDs.
+
+## Runtime output
+
+Production emits structured JSON to stdout for Docker collection. Development keeps readable console
+and debug output. The request middleware records method, path, status, elapsed milliseconds, trace ID,
+and authenticated subject when present. Unhandled errors use the same trace ID in their Problem Details
+response so an operator can correlate the client report with `docker logs`.
+
+Compose retains three 10 MB local log files per service. There is no external sink; add Seq/OTLP only
+when single-node Docker logs stop being operationally sufficient.