perf(server): speed up cold desktop launches

[Yash-Singh1]

Cold desktop launches spent time scanning orchestration events during the legacy-thread checks. Use the existing created-thread index for both startup queries.

In four isolated cold launches against the same V2 database snapshot, time to first window reveal improved by 7.3 seconds (66%). This measurement covers cold launches only.

Validation: focused importer tests, lint, and typecheck.

Model and harness: GPT-6 in Codex.

[macroscopeapp]

Approvability

Verdict: Approved at 9a5679b

Macroscope's review found this PR approvable — This is a small, self-contained SQLite query-plan optimization that forces an existing, migration-created index for two startup import checks. It preserves the queries' logical behavior and has plan coverage confirming the intended index is used.

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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	—	4.9 KiB	—	6.8 KiB	✅
Codex	Thread snapshot wire	—	3.7 KiB	—	4.9 KiB	✅
Codex	Live turn WebSocket wire	—	1.2 KiB	—	2.0 KiB	✅
Codex	Live turn WebSocket decoded	—	20.4 KiB	—	29.3 KiB	✅
Codex	Live turn messages	—	2	—	8	✅
Claude	Total thread wire	—	4.9 KiB	—	6.8 KiB	✅
Claude	Thread snapshot wire	—	3.7 KiB	—	4.9 KiB	✅
Claude	Live turn WebSocket wire	—	1.2 KiB	—	2.0 KiB	✅
Claude	Live turn WebSocket decoded	—	20.7 KiB	—	29.3 KiB	✅
Claude	Live turn messages	—	1	—	8	✅

Baseline: unavailable · PR result: 9a5679b · 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: 106.1 KiB
• Claude decoded thread snapshot: 106.4 KiB

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