fix(status-line): deduplicate PR lookups across instances

[designinglaunguage]

Closes #4331.

What changed

• adds a process-level PR lookup cache keyed by repository identity and branch;
• caches both positive and negative results for 60 seconds;
• shares an in-flight promise across status-line instances;
• preserves the existing instance-level branch/repository invalidation;
• adds regression tests for negative caching and concurrent deduplication.

Why

The existing instance cache accepts null, but long-lived render/config lifecycles can still produce repeated status-line instances/lookups. In observed use this spawned gh pr view --json number,url 5–28 times per 10 seconds and kept affected idle GJC processes at roughly 45–87% of one CPU core.

Verification

• focused tests: 31 pass, 0 fail
• TypeScript check: pass
• git diff check: pass

[Yeachan-Heo]

Maintainer intake — owning #4331 / #4332 (sole maintainer lane)

Taking ownership of this issue/PR pair. Exact state at intake:

• Remote PR head: 9839fbcf55dde5d5f91f812396fc7103db6d9deb (fork designinglaunguage/gajae-code, branch fix/status-line-pr-negative-cache)
• Submitted base: main@d915ffe58edddba8cb5f9cb9393b1943ebb6cc5c (stale relative to current dev)
• Current dev: e8af95c8332e588eb878b470dc6543c8645be74e
• Integrated candidate: e6ea5da32ef63eefd7fed69bd2e68c070be1c805 — your commit replayed onto current dev, verified patch-identical to 9839fbcf, authorship preserved
• CI: full run 31569177598 on 9839fbcf (still in progress at intake; attribution below covers terminal jobs so far)

CI attribution (run 31569177598):

• check job 94027314597 — PR-caused: Biome format fails only on packages/coding-agent/test/status-line-gh.test.ts (added multi-line import must collapse to one line). Reproduced locally with repo-pinned Biome 2.5.2 on the integrated candidate. Deterministic and in changed scope; fixing forward.
• Python SDK 3.10/3.11/3.12/3.13 — identical test_real_session_all_transports_cleanup socket-relay failure on all four; the changed files are TypeScript status-line only, so this is suspected pre-existing/environmental. Being verified against pristine dev before classification.
• coding-agent shards 3-of-16 and 4-of-16 — lifecycle-race failures outside the changed status-line files; under pristine-dev baseline comparison before classification.

Next: adversarial cache-lifecycle review + maintainer formatting repair, then baseline attribution, then a fresh exact-head CI signal. Review verdict follows.

— gjc maintainer lane (Yeachan-Heo) · worktree gajae-code-pr-4332-status-pr-cache · branch maintainer/pr-4332-status-pr-cache · head 9839fbcf55dde5d5f91f812396fc7103db6d9deb · base d915ffe58edddba8cb5f9cb9393b1943ebb6cc5c · dev e8af95c8332e588eb878b470dc6543c8645be74e · integrated e6ea5da32ef63eefd7fed69bd2e68c070be1c805 · CI run 31569177598

[Yeachan-Heo]

Maintainer disposition — fixed forward, integrating via #4348

Exact head reviewed: 9839fbcf55dde5d5f91f812396fc7103db6d9deb.

CI attribution on that head (run 31569177598):

• check — PR-caused: Biome format failure on the added multi-line import in status-line-gh.test.ts (repo-pinned Biome 2.5.2 requires collapsing to one line). Fixed forward with biome check --write, no behavior change.
• test, four test-shard jobs, Python SDK 3.10-3.13 — pre-existing/environmental, confirmed unrelated to this PR: identical failures reproduce on plain main@d915ffe58e with zero PR changes (CI run 31567860767), and a local check:sdk-closure seam-review failure reproduces identically on the git-stashed (unmodified) worktree.

Cache-lifecycle review of the diff itself: the in-flight lookup dedup and TTL cache with insert-time expired-entry sweep are correct — bounded process-lifetime memory, correct repo/branch key isolation, and correct clearCurrentPrCache drop-and-restart semantics, all covered by the added tests (13/13 passing locally, Biome clean after the format fix).

Integrated candidate targeting dev with the format fix on top, replayed with your authorship preserved: #4348. Closing this PR once #4348 lands; thank you for the fix.

—
[repo owner's gaebal-gajae (clawdbot) 🦞]

[Yeachan-Heo]

Integration complete — merged to dev via #4348

This PR was integrated, repaired, and merged into dev as PR #4348.

Merge commit: 9fd5f5ab1146262c990fe092198fb8fcad499407 on dev
Merged head: 5cfcf54b9dcb45f4941c0eda8636d82b23ea28f5

What was integrated from the original PR

• lookupCurrentPrCached with in-flight dedup + positive/negative TTL cache (60s) in gh.ts
• clearCurrentPrCache for test isolation
• Call-site switch in tool-status-header.ts to the cached lookup with repoId\0branch cache key
• 6 targeted cache lifecycle tests in status-line-gh.test.ts

Maintainer repairs on top (preserving original authorship)

1. Biome format fix: collapsed the multi-line test import to a single line (repo-pinned Biome 2.5.2 requirement). This was the sole PR-caused CI failure.
2. Bounded eviction: expired prCache entries are swept on every insert, bounding process-lifetime memory to keys seen within one TTL window.
3. PR-segment gating: #lookupPr() is no longer called when the status-line layout has no pr segment, eliminating an unnecessary gh spawn with no visible behavior change.

Contributor credit

Original cache design, in-flight dedup, and lifecycle tests by @designinglaunguage (commit 9e48240db1 / original fork head 9839fbcf5). All three PR commits retain the original authorship; maintainer repairs are in the third commit.

CI on the merged head

Dev CI run 31592802446 on 5cfcf54b9d (base bc2492af38): 22 success, 5 skipped, 0 failures.

Closing this PR as superseded by the merged #4348.

—
[repo owner's gaebal-gajae (clawdbot) 🦞]