[Bug]: A file marked Viewed after a push I have not loaded counts the pushed version as seen #35053

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

apps/web

Steps to reproduce

1. Open a Forgejo pull request in T3 Code, open its Code tab, and leave a file's diff on screen for more than a minute.
2. Push a commit that changes that file. Do not reload.
3. Tick the file as Viewed, then press Refresh pull requests.

Expected behavior

The file shows Changed, because the version I ticked is not the version that was pushed.

Actual behavior

The file shows Viewed, and after the refresh its diff shows the pushed lines I never saw. Nothing tells me the file changed. The same happens in the Linux desktop app.

Impact

Minor bug or occasional failure

Version or commit

main, commit 1a1f9ac (run from source)

Environment

Linux, web client in a Chromium-based browser and the Linux desktop app, a local Forgejo 17 server

Logs or stack traces

Screenshots, recordings, or supporting files

Web, main 1a1f9ac, after the refresh: greeting.ts Viewed (1 / 3) over the "friend" diff

Workaround

A fix is in #24151.