v0.21 release audit: integrated state, verification, QA walkthrough and runbook

[raiseCatError]

Refs #410. Docs plus one QA helper script; no product code.

What changes

• docs/development/v021-ledger.md now records the integrated state: Docs: v0.21 design, acceptance and ledger #411–v0.21 ledger: stabilization findings, verification, ordered integration and release gates #424 merged into dev (433af8fd), with each merge commit.
  • Exact-commit CI: push run 39135227830, all 13 jobs green.
  • Local gates on 433af8fd: npm ci, build, benchmark typecheck, bench:smoke and git diff --check pass. The suite ran 3,139 / 3,142 with 2 skipped and 1 failure, analysed below.
  • Benchmarks, and the code review's findings and disposition.
  • The remaining release gates.
• docs/testing/v021-physical-qa.md:
  • New item 3.9 for /edit: a new file in a symlinked folder saves again without a false conflict #425.
  • Isolation and build-under-test notes.
  • The items this Mac cannot run, with the coverage that exists instead.
  • A walkthrough: the 12 passes grouped into three sittings (Ghostty zsh; Terminal.app Fish; Terminal.app zsh), each with exact commands and expected results, and how to report results.
• scripts/qa/v021-fixtures.sh <new folder> creates every fixture the walkthrough uses: progress displays, hostile, FIFO and 20 MB files, CRLF+BOM, symlinks, 0640 and read-only files, passing and failing test projects, TypeScript and C errors, a small git repo, a Bun project.
  • It also creates a launcher (./nmsh [zsh|bash|fish|copy]) that runs the QA build with its own XDG_CONFIG_HOME and NMSH_RUNTIME_DIR, so it never reads your settings or attaches to your running sessions.
  • Nothing outside the folder is changed; nothing is downloaded, installed or run as root.
• docs/development/v021-release-runbook.md: the v0.20 release flow made exact for v0.21.0, verified against the repository and the tap:
  • the release branch, then a merge commit into master, then the annotated tag on it, then the GitHub release (no assets);
  • verifying the archive checksum;
  • a manual tap PR (autobump failed daily from 2026-10-13 to 10-17), then the website sync after the tap, then the approved manual publish;
  • post-release smoke, dev fast-forward, and rollback.

Findings recorded

• /edit: a new file in a symlinked folder saves again without a false conflict #425: /edit fix (new file in a symlinked folder: a false conflict on the second save).
• Input ownership test: type the follow-up after the answered command completes #427: test race in inputOwnershipLive. This was the CI failure on /edit: a new file in a symlinked folder saves again without a false conflict #425 and most local parallel failures.
• Under heavy load, a reply typed right after a prompt-less read starts can be queued instead of answering it #426: pre-existing product behavior under heavy load (a reply to a prompt-less read can be queued).
• Flaky: Fish adapter lifecycle test teardown races fish_update_completions #403 closed (verified). Draft Track live commands with /track (initial slice of #393) #394 closed as superseded by /track: one live result of a finite command, refreshed in place (#393) #416.

Verification

• git diff --check: pass.
• The fixture script was run into a fresh T7 folder. Each fixture was checked for what its item needs, and the captured test and compiler outputs went through the real recognizer: passing tests give node --test: 8 passed · 0 failed (40 in the final script); failing tests give 2 failed with 2 items; TypeScript gives 2 errors; GCC/Clang gives 1 error.
• The launcher was started headless for zsh, Bash and Fish only to confirm it starts (it reaches the composer with no setup screen and leaves no session behind). That is not physical QA.