Needs audit: Codex parent wait discipline (registry rule)

[Trecek]

Summary

Deliver a concise, evidence-bound Codex parent-coordination rule through CODEX_INTAKE_RULES. The existing Codex intake digest carries it to interactive, headless, resume, orchestrator, and generated sub-agent instruction paths; Claude Code does not receive the Codex intake digest.

The injected rule is:

After delegating, wait for every active sub-agent; do not duplicate their work. While they run, only do work the user explicitly requests.

This replaces the initial cook-only backend capability and removes the associated command-test churn.

Verification

• task test-check — 11,439 passed, 138 skipped, 12 xfailed
• pre-commit run --all-files — all hooks passed
• Codex intake digest: 1,044 → 1,185 bytes (1,200-byte budget)
• Complete Codex discipline suffix: 2,996 → 3,137 bytes; declared ceiling raised deliberately from 3,000 to 3,150 bytes

Related issue

Closes #4447

[Trecek]

Corrected the implementation in 6406760d49f88ce5b99bef72ac737dc33479b78c after reviewing the scope against #4447:

• Replaced the fresh-cook-only backend capability with an evidence-bound CODEX_INTAKE_RULES entry, so the instruction follows all existing Codex delivery paths and remains absent from Claude Code.
• Reduced the instruction to one 138-byte rule with the explicit user-request exception.
• Removed the backend/cook-specific test churn and retained focused registry coverage.
• Validation: task test-check passed 11,439 tests; pre-commit run --all-files passed all hooks.