Revoked tokens stop being invisible: popup plate + token ID, tokens table columns ...

Extension 0.2.2: a 401 from any API call flips a tokenInvalid flag that the
popup renders as a dedicated plate (same load, via status propagation from
the background, plus the pre-flagged check on popup open); the Settings
drawer shows the stored token's public ID so it can be matched against the
tokens table. Web: Tokens tab gains Public ID / Created / Last used columns.
Design pack v24 ships the new strings (en/uk/ru); served zips rehashed.

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

Import browser extension source under extensions/extension ...

Move the gnexus-creds-extension sources (Chrome/Firefox MV3) from the
separate sibling repository into extensions/extension/ so builds live
next to the packaged releases this service distributes
 (extensions/dist/ + extensions/manifest.json, untouched).

- add a reproducible `make lib` target materializing lib/ from the
  frontend's pinned gnexus-ui-kit (gitignored, like before)
- drop the playwright-only package.json/lock; system node+zip suffice
- scoped .gitignore so it cannot shadow tracked extensions/dist zips
- README (main + extension): document the in-repo build and publish flow

Rebuilt zips differ from released ones only in the three lib files
(older kit in the release); extension code itself is byte-identical.

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