fix: harden restart recovery and release smoke

[numnx]

What changed

• Recover a completed QA coding follow-up after a runtime restart and continue Git finalization without dispatching a duplicate provider invocation.
• Preserve durable QA continuation timestamps and provider completion checkpoints for both task and sprint QA paths.
• Make the settings persistence Playwright flow retry-safe and wait for the restored active navigation state.
• Retry only the known transient Windows NSIS access violation once in a fresh install directory.
• Let the macOS release smoke harness terminate an already validated packaged app, accepting both a direct signal exit and the embedded server's clean signal-handler exit.
• Upload native release-candidate artifacts whenever packaging succeeded, including when the installed-app smoke fails.
• Update restart and desktop release documentation across canonical and published docs.

Why

The release matrix exposed four independent reliability gaps: duplicate QA repair work after restart, a retry-sensitive settings test, a transient Windows installer crash, and a macOS Electron process that reached renderer readiness but did not self-exit. These changes close those gaps without weakening orchestration or release verification.

Validation

• node_modules/.bin/tsc --noEmit — passed
• node scripts/build.mjs — passed
• Backend Vitest — 467 files passed; 6,150 passed, 12 skipped
• Dashboard Vitest — 272 files passed; 2,537 passed, 1 skipped
• Full settings Playwright project — 21 passed
• Notion persistence Playwright with --repeat-each=3 — 3 passed
• Focused QA, workflow, and Electron tests — passed
• Docker ci-qa-dag with two forced runtime restarts — passed; all four tasks merged, one intended QA follow-up, sprint QA passed, no dependency violations, no remaining volumes

Risk and rollback

• QA recovery is limited to a running durable continuation, the same provider/task run, and a completed invocation at or after the recorded workspace baseline (or an exact persisted checkpoint).
• Windows retry is limited to 0xC0000005 and one additional attempt.
• macOS harness termination occurs only after the packaged renderer-ready marker validates successfully.
• Roll back commit 22ca5d3a0 if release smoke or continuation behavior regresses.