GEN-2116: Refresh jobs and run pages through lifecycle changes

[asselstine]

Jobs and job detail pages now discover new runs and update lifecycle state automatically. Run detail refreshes its status, kill control, live indicator, and artifact status through completion without replacing the trace or open prompt disclosure.

• Shared completion-based polling runs every 3 seconds while active and every 10 seconds for idle job pages or pending terminal artifacts. It pauses in hidden tabs, refreshes on focus/return, and retries failures with capped exponential backoff.
• Job refresh preserves the selected cursor page, open details, keyboard focus, and manual prompt drafts; unchanged responses retain the existing DOM.
• Trace reads remain incremental and bounded to 100 events. Load more and automatic refresh are serialized, including a final fetch after an in-flight request when a run completes. Settled terminal runs stop polling.

Validation: npm run check passed (159 tests, including 11 new browser lifecycle cases; API boundaries; workspace TypeScript; app and tail-relay Worker dry-run builds). git diff --check passed.

Reviewed #176, #175, #172, and #169. This change is based on main and only changes refresh orchestration/lifecycle UI; timing calculations, provenance, run titles, trace presentation, and backend finalization are unchanged. Those PRs share long lines in ui.ts, so their additions should be retained when resolving merge conflicts.

Fixes GEN-2116: https://linear.app/generation/issue/GEN-2116/updates-to-page

[linear]

GEN-2116