Brand gateway password page

[dankritz]

Summary

• Restyles the gateway external-password page to match the VibeStack palette and typography.
• Adds the Dendrix/VibeStack logo to the standalone auth page through a public API asset route.
• Adds explanatory copy and a link to https://dendrix.ai.
• Adds a regression test for the branded password page output.

Validation

• npm run typecheck
• npm test --workspace @vibestack/api
• npm run build --workspace @vibestack/api
• git diff --check

Publication note

After merge, publish nightly to the merged commit and rebuild the live server.