backstage release v3.3.0

(muster) MCP sign-in notice on every page, with a sign-in dialog by @teemow — Where the Agent Platform is on, a card in the bottom right of every page says which MCP servers still need your sign-in or grant. Sign in opens a dialog to finish each of them, and Not now hides the card for the browser session. Covers the home installation’s muster.

(agent-platform) Name the platform team when Installations is off by @teemow — On a portal without the Installations page, the kagent is not installed card says to ask your platform team to enable the Agent Platform instead of pointing at a page the person cannot open.
(muster) Never forward an expired Dex ID token; refresh or ask to sign in again by @teemow — A tab left open past the sign-in token’s lifetime no longer shows muster’s raw token has expired … re-authenticate errors. The portal refreshes the session before the token lapses, and when it cannot, shows Your session expired, sign in again. with Sign in again.
(ui-react) Keep a tab’s width while its count loads and arrives by @marians — Tabs with a count, on Customize, a connector’s Tools and a skill’s Used by, no longer shift sideways when their numbers load, so a click no longer lands on the neighbouring tab. A placeholder holds each number’s place.

Full Changelog: https://github.com/giantswarm/backstage/compare/v3.2.0...v3.3.0