[yaacovcorcos]

What Changed

Test-only. In apps/mobile/src/features/diffs/nativeReviewDiffHighlighter.test.ts, the real-Shiki test wrapper now passes tokenizeTimeLimit: 0. The grammar is still the real one; only its wall-clock cutoff is off in these tests. The edit is a marked seam in an upstream-owned test, with an UPSTREAM.md note.

Why

highlightNativeReviewDiffVisibleRows > keeps grammar state across inline comment rows dropped #567 from the merge queue. It failed with expected { 'template-open': [ …(3) ] … } to deeply equal { 'template-open': [ …(5) ] … }.

• Cause: Shiki's default 500 ms per-line limit makes it return partial tokens and incomplete grammar state on a busy runner. The test compares two separately timed calls, so they can disagree.
• Proof: Codex faked Date.now() so the limit trips mid-test. That reproduced the exact CI diff (3 tokens instead of 5) 5 of 5 times. With this change, it passed 5 of 5.
• Upstream: the file is upstream-owned and is unchanged through upstream a71a6c37d1, so there was no upstream fix to bring in.

Not changed here: production keeps Shiki's time limit. That means a very slow line can still leave later rows miscoloured in the mobile diff view. Fixing that is a separate decision about responsiveness.

Documentation Impact

Documentation impact: Updated — UPSTREAM.md (test-only override to keep when syncing).

Verification

• Focused file: 14/14 passed on Windows.
• Reproduction: the forced-timeout case fails 5/5 without the fix and passes 5/5 with it.
• Repository checks: format, lint, typecheck, build and git diff --check passed.

Checklist

• This PR is small and focused
• I explained what changed and why
• I included before/after screenshots for any UI changes (no UI change)
• I included a video for animation/interaction changes (none)

Root cause and fix: Codex gpt-6.1-sol. Publication: Claude Opus 5.5 in Claude Code (Scient).

🤖 Generated with Claude Code

[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	5.6 KiB	5.6 KiB	0 B (0.0%)	6.8 KiB	✅
Codex	Thread snapshot wire	4.3 KiB	4.3 KiB	0 B (0.0%)	4.9 KiB	✅
Codex	Live turn WebSocket wire	1.3 KiB	1.3 KiB	0 B (0.0%)	2.0 KiB	✅
Codex	Live turn WebSocket decoded	26.2 KiB	26.2 KiB	0 B (0.0%)	29.3 KiB	✅
Codex	Live turn messages	2	2	0 (0.0%)	8	✅
Claude	Total thread wire	5.6 KiB	5.6 KiB	0 B (0.0%)	6.8 KiB	✅
Claude	Thread snapshot wire	4.3 KiB	4.3 KiB	0 B (0.0%)	4.9 KiB	✅
Claude	Live turn WebSocket wire	1.3 KiB	1.3 KiB	0 B (0.0%)	2.0 KiB	✅
Claude	Live turn WebSocket decoded	26.6 KiB	26.6 KiB	0 B (0.0%)	29.3 KiB	✅
Claude	Live turn messages	2	2	0 (0.0%)	8	✅

Baseline: d9f0b39 · PR result: ef117f8 · Source CI: success

Scenario and decoded snapshot size

10 historical turns, 5 command tools per turn, 878.9 KiB retained MCP result per historical turn, and a 1.05 MiB retained result in the measured turn.
Full compact HTTP snapshot with live cursor.

• Codex decoded thread snapshot: 133.1 KiB
• Claude decoded thread snapshot: 133.4 KiB

Updated in place by a trusted workflow. PR artifacts are strictly validated and never executed.