backstage release v3.9.4

(agent-platform) Name the input and output tokens behind the cost estimate by @marians — The note under Est. cost in a session’s cost popover and on the Usage page names the input and output tokens the estimate is based on, and how many other tokens, such as thinking, it leaves out.
(app, gs) Footnotes jump in template descriptions, step notes and access docs by @teemow — Footnote references jump to their notes in a template’s description, a template step’s note and an installation’s access docs. A step note’s text is now the same size as other markdown in the portal.
(several plugins) One session-expired message instead of two by @teemow — An expired portal sign-in reads Your session expired, sign in again. everywhere, including the Cluster access status, which had its own wording. A rejected one reads Your session was rejected, sign in again.

(app, gs) Every Login Required caller is named; two e2e specs stop flaking by @teemow — Every part of the portal that may open the Login Required dialog names itself in the page while it waits. Two browser tests that flaked now wait for what they check.
(deps) Update tanstack-query monorepo to v5.104.1 by @renovate[bot]
(e2e) A shell-mode agentlab run on a classic-only lab fails, never skips by @teemow — A browser test run for the Agent Platform shell against a lab serving only the classic portal fails with the cause, instead of skipping every test and passing.

Full Changelog: https://github.com/giantswarm/backstage/compare/v3.9.3...v3.9.4