fix(mobile): stabilize iOS header item transitions

[rynfar]

Adopts upstream #8607 (4669eab8e) from the f94a0d646..bcb855a63 review.

Its only conflict was pnpm-lock.yaml. Taking Pylon's side alone left the lock stale — #8607 also edits native patches, so a frozen install failed with ERR_PNPM_LOCKFILE_CONFIG_MISMATCH on patchedDependencies. The lock was regenerated from the merged manifests instead, and vp i --frozen-lockfile now passes.

This lands ahead of the Expo SDK 57 upgrade, which builds on the same react-native-screens patch. Rebasing that work onto this branch dropped its conflicts from 40 to 5.

Model: Claude Opus 5. Harness: Claude Code.

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[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	13.3 KiB	13.5 KiB	+220 B (+1.6%)	15.1 KiB	✅
Codex	Thread snapshot wire	6.9 KiB	6.9 KiB	+7 B (+0.1%)	7.3 KiB	✅
Codex	Live turn WebSocket wire	6.4 KiB	6.6 KiB	+213 B (+3.3%)	7.8 KiB	✅
Codex	Live turn WebSocket decoded	55.5 KiB	57.0 KiB	+1.5 KiB (+2.7%)	66.4 KiB	✅
Codex	Live turn messages	9	11	+2 (+22.2%)	21	✅
Claude	Total thread wire	13.3 KiB	13.3 KiB	−38 B (−0.3%)	15.1 KiB	✅
Claude	Thread snapshot wire	6.9 KiB	6.9 KiB	−3 B (−0.0%)	7.3 KiB	✅
Claude	Live turn WebSocket wire	6.4 KiB	6.4 KiB	−35 B (−0.5%)	7.8 KiB	✅
Claude	Live turn WebSocket decoded	56.4 KiB	56.3 KiB	−44 B (−0.1%)	66.4 KiB	✅
Claude	Live turn messages	10	9	−1 (−10.0%)	21	✅

Baseline: abe70a7 · PR result: 0fca43b · 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.

• Codex decoded thread snapshot: 109.4 KiB
• Claude decoded thread snapshot: 110.1 KiB

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