v0.9.105 — Steadier session switching, email-code sign-in, and a batch of fixes

Fixed

• Switching between sessions no longer flashes a "Something went wrong" screen. A brief "runtime still starting" state during a session switch now shows a short loader and recovers on its own instead of surfacing as an error.
• The review inbox (sidebar and Review Center) keeps loading even when one of its sources is temporarily unavailable — it now degrades gracefully instead of failing the whole panel.
• Session file uploads are recoverable again after an interruption.
• PDF previews now open at 100% zoom instead of 50%.
• Sign-in polish on mobile: the mark is pinned top-left, gutters are wider, and the tagline is refreshed.

New and improved

• Signing in now defaults to a one-time email code, with password kept as a secondary option.
• Projects still on the older manifest now show a clear v1 → v2 upgrade prompt in the sidebar.
• Maintenance mode: admins can bypass a full lockdown through a signed session, and deploys now raise a heads-up banner while a rollout is in progress and clear it automatically once the API is healthy.

What's Changed

• chore(release): VERSION → 0.9.105 [skip ci] by @github-actions[bot] in #4486
• chore(dev-eks): deploy dev-9f6fa472 [skip ci] by @github-actions[bot] in #4488
• fix(web): render nothing for transient runtime-not-ready (info, not an error) by @markokraemer in #4489

Full Changelog: v0.9.104...v0.9.105