Restore the system prompt after context compaction

[TheGreatAxios]

Summary

• After context compaction, ChatDirector and SubAgentDirector infer with the constructor system prompt so Codex requests keep instructions
• Compacted-history adapter snapshot locks instructions plus user-summary input with no developer item

Verification

• bun run typecheck, bun run build, and bun run test pass
• bun run check passes

Fixes CL-7533

[linear-code]

CL-7533

[TheGreatAxios]

Critic · Comment

Post-compact ChatDirector and SubAgentDirector infer actions now carry the constructor systemPrompt. Codex buildRequest still maps that field to instructions with no developer item. Adapter snapshot locks compacted history.

No blocking findings.

Keep: director compact-resume assertions, subagent overflow resume systemPrompt, open-task nudge keeps stable-base plus ephemeralTurns, compacted-history adapter snapshot.

[TheGreatAxios]

Verdict: approve (cannot GitHub-approve own PR).

CL-7533 holds at 16451e8f. ChatDirector and SubAgentDirector default constructor systemPrompt on infer rewrite, so compaction resume and ChatDirector abort recovery keep Codex instructions. Compacted-history adapter test locks instructions + user-summary input with no developer item. Explicit systemPrompt still wins via ??.

No blocking findings. File-for-later: the two injection sites still inline the same default instead of a shared production helper (HEAD title said "share the helper"; the shared helper is the test factory).

[TheGreatAxios]

Verdict: approve (GitHub cannot approve own PR).

CL-7533 holds at 16451e8f. ChatDirector and SubAgentDirector default constructor systemPrompt on infer rewrite, so compaction resume and ChatDirector abort recovery keep Codex instructions. Compacted-history adapter test locks instructions + user-summary input with no developer item. Explicit systemPrompt still wins via ??.

No blocking findings. File-for-later: the two injection sites still inline the same default instead of a shared production helper (HEAD title said share the helper; the shared helper is the test factory).