Fix fresh-task subject capture race [BEAR-104]

[ericlitman]

Summary

• replace timing-dependent first-title adoption with a reserved model-supplied subject seed
• use the seed only when an unowned fresh task still exposes its raw/truncated first message; preserve explicit names, generated titles, exact committed ownership, lost-Post recovery, persistent-home identity, and later user renames
• fail closed on missing, malformed, empty, overlong, raw-message, or delegation-envelope running markers
• align install migration inventory with the native addressable catalog and keep one resumable serial controller as the only historical-title writer
• update managed guidance, architecture, release QA, public installer guide, and hosted release smoke

Verification

• gofmt clean and git diff --check
• go test ./...
• go test -race ./...
• go vet ./...
• sh -n install.sh and sh -n scripts/release-smoke.sh
• cmp INSTALL.md site/install and installer parity
• Darwin arm64 and amd64 release-style v2.1.1 builds, embedded-version checks, SHA-256 verification
• arm64 v2.1.1 version --json and candidate self-test --json
• production Go: 1,000 lines (target ceiling 1,000)
• shipped executable logic: 1,262 lines (absolute ceiling 1,500)
• Fable implementation and release-plan reviews: Ship

Live lifecycle gate

• real fresh foreground direct and delegated-envelope canaries rendered correct running and terminal titles in both active header and mounted sidebar
• 20-turn / 40-operation capability matrix passed, including explicit targets, target isolation, stop behavior, and 60-UTF-16 limits
• real 200-task serial migration was interrupted after 20 writes and resumed under the same controller to 200/200; a 48-task residual pass reached zero
• keep-title uninstall, genuine Codex restart, candidate reinstall, second genuine restart, and fresh direct/delegated canaries passed
• post-reinstall migration completed under the same controller: 259 serial writes, 259 exact tool results and native readbacks, zero retries/drift, one applied-running root skip, 260/260 applied, zero remaining
• final installed candidate reports migration_complete, ready=true; self-test and idle 0-stdout / 0-model / 0-write gates passed
• completed controller archived; persistent home is exactly 🧵🐻 ThreadBear 🐻🧵, pinned, and visibly rendered in the sidebar

Release

• stable target: v2.1.1
• release commit: 365743a0c56b9cae34b9224c6ac3703184c8fd36
• code candidate head: 4bddd663b61ea7b18a959df77a40fe9b53575bc6
• Open SWE review finding fixed in 365743a; hosted-smoke fixture reproduction passes and the review thread is resolved
• candidate 2.1.0-bear104.7 arm64 SHA-256: 297ee14331df7562adb4f71a83db120177c7273edda154437aeb58469e350e30
• release-style v2.1.1 arm64 SHA-256: 0590ac844ad90d56fbc4dbe862b2edc6672eafcbf98f322691db04a0255fc741
• release-style v2.1.1 amd64 SHA-256: 129b06a72b0051106d9261ca025449e5fd5ef183b35b768c8c7aec987ee23641

Linear: BEAR-104

[mobilyze-open-swe-studio2]

Open SWE Review found 1 potential issue.

Open in Web

[mergify]

Merge Queue Status

• ✅ Entered queue — 2026-08-02 06:31 UTC · Rule: default · triggered by merge protections
• ✅ Checks skipped · PR is already up-to-date
• ✅ Merged — 2026-08-02 06:32 UTC · at 365743a0c56b9cae34b9224c6ac3703184c8fd36

This pull request spent 8 seconds in the queue, including 1 second running CI.

Required conditions to merge

• github-review-approved [🛡 GitHub repository ruleset rule Mergify automatic merge queue]
  • Fix fresh-task subject capture race [BEAR-104] #102
• all of [🛡 Merge Protections rule Queue ready pull requests]:
  • -draft
    • Fix fresh-task subject capture race [BEAR-104] #102
• 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