improvements: parallelize refreshGit sub-calls and gate polling on focus

[matiaspalmac]

[Improvement]: Parallelize refreshGit sub-calls and gate polling on focus

Description

refreshGit in GitExplorerComponent.tsx awaited four independent git
invocations in sequence:

1. get_git_status
2. get_git_branches
3. git_log
4. git_stash_list

Each one spawns its own backend git child process, so the chain took
roughly the sum of the four call latencies — measured in the
~150-400 ms range per 5 s poll cycle on realistic repos. Running them
concurrently drops that to roughly the max of any single call, and
the interval itself still ran full-speed while the window was visible
but unfocused, which dominated idle CPU on battery.

Change

All in apps/desktop/src/addons/builtin.git-explorer/GitExplorerComponent.tsx:

• Parallel dispatch. The four sub-queries now go through
  Promise.allSettled together instead of sequential awaits. A
  failure in any one no longer aborts the rest — git_log on a repo
  with zero commits used to throw and silently drop status parsing
  mid-flight; now each result is handled independently.
• Status drives the fallback. The "dubious ownership" detection
  and the no-repo empty-state still key off the get_git_status
  rejection specifically. The other three degrade to empty arrays if
  they fail, which matches the old per-call try/catch for log and
  stashes.
• Tighter polling guard. The 5 s interval now also checks
  document.hasFocus(). visibilityState === "visible" was too loose:
  a visible-but-unfocused window (user typing in the browser) still
  cost a full git refresh every 5 s.
• Snap back on refocus. Added a window.addEventListener("focus", …) handler that triggers a refresh immediately when the user
  returns, instead of showing up-to-5-s-stale data until the next
  tick.

Trade-offs

• Point 3 of the issue suggested collapsing the four calls into a
  single Rust get_git_snapshot command that runs them concurrently
  inside tokio. That is a larger change (new command, new type
  bindings, more CI surface) and is out of scope for this PR — the
  JS-side Promise.allSettled already captures the performance win
  with a single-file diff.
• Promise.allSettled fires all four processes even on a non-git
  directory (the get_git_status rejection branch only runs after
  all four settle). That is a wash in practice: the three other calls
  fail fast on the same "not a git repository" error path the status
  call takes.
• The focus-based refresh triggers on every window focus while the
  git tab is active. That is intentional — users expect fresh state
  after stepping away — and the existing gitLoadingRef guard
  prevents overlapping refreshes from stacking up.

Verification

• pnpm tsc --noEmit across the desktop app → clean.
• pnpm eslint on the touched file → 0 findings.
• Manually traced all four Promise.allSettled branches:
  • All succeed → state updated exactly as before.
  • Only git_log fails → log clears, rest renders.
  • get_git_status fails with "dubious ownership" → existing confirm
    dialog fires and retries.
  • get_git_status fails with "not a git repository" → silent
    empty-state branch, same as before.

Related Issue

Closes #84

Checklist

• I have checked for existing feature requests.
• I have followed the project's coding guidelines.
• Documentation has been updated (if applicable).
• My changes generate no new warnings or errors.

[github-actions]

Thanks for the contribution! I'll review it as soon as possible. If you have still changes, please mark this PR as draft and all reviews will be cancelled. Tests reviews will be re-run only when the PR is marked as ready for review.

[Copilot]

Pull request overview

This PR optimizes the Git Explorer’s periodic refresh behavior by reducing backend git process latency and avoiding refresh work when the app isn’t focused, improving responsiveness and lowering idle CPU usage in the desktop app.

Changes:

• Parallelized the four independent refreshGit backend invocations via Promise.allSettled, handling each result independently.
• Updated error handling so get_git_status remains the source of truth for “not a repo” / “dubious ownership” fallback behavior.
• Tightened polling to require document.hasFocus() and added an immediate refresh on window focus.

---

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.