sync: finish upstream alignment through bc8584bf8e

[aaditagrawal]

Incorporates eight upstream commits published during the alignment audit, through bc8584bf8e967ecc1cd215d42bd7a47faf51a862. The final stack now contains all 156 upstream commits missing after #266.

Adopts file grammar readiness before editing, selected diff-file reveal, deduplicated PR project choices, private test helpers, obsolete preview-helper cleanup, and browser keybinding notice spacing. Retains the fork SDK dependency patch and all preceding provider/runtime adaptations.

Validation: 43 focused tests across six affected web/mobile/client-runtime files; full workspace check/typecheck; preserved exact cold/warm highlighting regression. Integrated browser verification opened a cold syntax-highlighted JSON editor with editing enabled and inspected keybinding settings. Final branch is zero commits behind the stated upstream snapshot. No release or merge to main is included in this PR.

[aaditagrawal]

• sync: finish upstream alignment through bc8584bf8e #273 👈 (View in Graphite)
• fix(providers): preserve custom model descriptors and restore Copilot startup #272
• refactor(web): remove unused legacy client modules #271
• perf(cursor): retain compact turn summaries instead of SDK streams #270
• fix(providers): reject unsupported rewind before restoring files #269
• sync: complete upstream alignment through 7a089b2b24 #268
• sync: adopt upstream streaming and persistence performance work #267
• sync: integrate remaining upstream commits through 09d13de43 #266
• sync: integrate upstream wave 4 (settings reorg, usage limits, compaction) #265
• sync: integrate upstream wave 3 (Antigravity + cookie import) #264
• sync: integrate upstream wave 2 through 652515a34 #263
• sync: integrate upstream wave 1 through 355fbd96d #262
• main

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[github-actions]

Thread transfer impact

✅ Thread transfer remains within every enforced ceiling.

ℹ️ No successful main baseline artifact is available yet. This run establishes the initial measurement.

Provider	Metric	Main baseline	This PR	Impact	PR ceiling
Codex	Total thread wire	—	13.5 KiB	—	15.1 KiB	✅
Codex	Thread snapshot wire	—	7.0 KiB	—	7.3 KiB	✅
Codex	Live turn WebSocket wire	—	6.4 KiB	—	7.8 KiB	✅
Codex	Live turn WebSocket decoded	—	56.2 KiB	—	66.4 KiB	✅
Codex	Live turn messages	—	8	—	21	✅
Claude	Total thread wire	—	13.5 KiB	—	15.1 KiB	✅
Claude	Thread snapshot wire	—	7.0 KiB	—	7.3 KiB	✅
Claude	Live turn WebSocket wire	—	6.5 KiB	—	7.8 KiB	✅
Claude	Live turn WebSocket decoded	—	57.8 KiB	—	66.4 KiB	✅
Claude	Live turn messages	—	8	—	21	✅

Baseline: unavailable · PR result: 6420917 · 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: 113.9 KiB
• Claude decoded thread snapshot: 114.6 KiB

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

[aaditagrawal]

Merge activity

• Sep 5, 7:41 AM UTC: A user started a stack merge that includes this pull request via Graphite.
• Sep 5, 7:43 AM UTC: Graphite couldn't merge this pull request because a downstack PR sync: integrate upstream wave 2 through 652515a34 #263 failed to merge.