CI: unbounded apt steps consume the whole job budget and report as opaque job timeouts

Start with .github/workflows/ci.yml lines 159-183 and 271-272, reading the two apt-related workflow steps and their existing job timeouts. Add bounded step-level handling for both installation steps, then validate the workflow syntax and confirm that an installation failure is reported at the step rather than only as a job timeout.

Summary

Two CI steps run apt with no step-level time bound. When a package mirror is slow, the step consumes the entire job budget and the job dies at timeout-minutes. The failure surfaces as a generic job timeout, which is indistinguishable from a slow build or a hung test — no test ever runs.

This has burned at least five jobs across four runs in ~13 hours, including three on main.

The two steps

• .github/workflows/ci.yml:271-272 — Install Playwright system dependencies → pnpm exec playwright install-deps chromium (apt under the hood). Job timeout-minutes: 30.
• .github/workflows/ci.yml:159-183 — Install Tauri dependencies (Linux) → apt-get update + apt-get install. Job timeout-minutes: 45.

Both already pass Acquire::Retries=3 and Acquire::http::Timeout=30. Those bound an individual request; neither bounds the step, so a mirror that is slow-but-not-dead is retried until the job budget is gone.

Observed occurrences

In every case each preceding step succeeded and every following step is skipped. Annotation is always The job has exceeded the maximum execution time of 30m0s / 45m0s — nothing names apt, which is what makes this expensive to diagnose. The PR that surfaced it (#5946) changes only six files under docs/.

Why it's worth fixing rather than re-running

The failure is silent about its own cause. A reviewer sees "Desktop Core timed out at 45m" and reasonably suspects a build regression; the actual event is a package mirror being slow during a ~4-minute apt install. Re-running works often enough that the underlying tax stays invisible.

Suggested fix

Bound the step so it fails fast and says what happened:

- name: Install Playwright system dependencies
  timeout-minutes: 10
  run: cd desktop && pnpm exec playwright install-deps chromium

and likewise for the Tauri deps step. A step-level timeout-minutes turns a 30-minute silent budget burn into a fast, correctly-attributed failure. Optionally add -o Acquire::http::Dl-Limit / an overall timeout wrapper, but the step bound is the part that makes the diagnosis obvious.