fix: remove ordinary-turn title delay [BEAR-107]

[ericlitman]

What changed

• replace the 2.8-5 KB model-generated ordinary-turn policy cell with a 219-byte uncached loader
• emit the reviewed policy from the verified ThreadBear binary with the typed current-task plan already bound
• keep mounted codex_app__read_thread / codex_app__set_thread_title as the sole ordinary-turn reader and writer
• add focused loader/program failure tests, release-smoke coverage, docs, and the v3.0.3 changelog section

Why

The local helper and mounted APIs were fast, but Codex spent a measured 16.7 seconds on average generating the prescribed policy cell before every final response. The new loader removes that repeated serialization without adding SQLite, App Server, state, cache, daemon, retry, queue, controller, fallback, or a second writer.

Verification

• go test ./... -count=1
• go test -race ./... -count=1
• go vet ./...
• python3 scripts/validate-experiments.py
• Darwin arm64 and amd64 cross-builds
• shell syntax and installer/site parity
• exact v3.0.3 candidate release smoke passed twice
• exact candidate installed byte-for-byte, Codex restarted, self-test/status/updater healthy
• live mounted canary visibly removed and restored the status icon in both active header and sidebar
• final post-restart no-write loader executor: 0.4s; issued mounted operation range: 0.3-1.0s
• Fable completion gate: Ship
• independent read-only review-agent: Pass, no findings

Linear: BEAR-107

[openswebot]

Open SWE Review found 2 potential issues.

Open in Web

[mergify]

Merge Queue Status

• ✅ Entered queue — 2026-08-21 20:28 UTC · Rule: default · triggered by merge protections
• ✅ Checks skipped · PR is already up-to-date
• ✅ Merged — 2026-08-21 20:29 UTC · at 0bf00854c88557b36305f94f6015a4c0c600f4d3

This pull request spent 32 seconds in the queue, including 5 seconds running CI.

Required conditions to merge

• github-review-approved [🛡 GitHub repository ruleset rule Mergify automatic merge queue]
  • fix: remove ordinary-turn title delay [BEAR-107] #129
• all of [🛡 Merge Protections rule Queue ready pull requests]:
  • -draft
    • fix: remove ordinary-turn title delay [BEAR-107] #129
• any of [🛡 GitHub branch protection]:
  • check-success = verify
  • check-neutral = verify
  • check-skipped = verify
• any of [🛡 GitHub branch protection]:
  • check-success = Open SWE Review
  • check-neutral = Open SWE Review
  • check-skipped = Open SWE Review
• any of [🛡 GitHub repository ruleset rule Mergify automatic merge queue]:
  • check-success = @mergify/Mergify Merge Protections
  • check-neutral = @mergify/Mergify Merge Protections
  • check-skipped = @mergify/Mergify Merge Protections
• any of [🛡 GitHub repository ruleset rule Review gate]:
  • check-success = Open SWE Review
  • check-neutral = Open SWE Review
  • check-skipped = Open SWE Review