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/cv-builder/exports.md

@@ -1,3 +1,8 @@
 # exports
 
-TODO: Complete documentation.
+Authenticated variant export uses `POST /api/cv/variants/{id}/export-pdf`. The server resolves the
+variant against the current Career Profile, renders HTML through `ThemedCvRenderer`, and invokes
+headless Chromium through `PlaywrightCvPdfExporter`.
+
+Public variants expose the same render through `GET /api/public-cv/{slug}/pdf`; visibility is checked
+before rendering and anonymous generation is limited to three requests per public link per minute.