[Feat] Add merged and closed PR status to task history

[roomote-roomote]

Opened on behalf of Matt Rubens. Follow up by mentioning @roomote-roomote, in the web UI, or in Slack.

Related issue

Internal work from Slack (no tracked issue).

Why this PR exists

• A maintainer explicitly invited this PR in the linked issue or discussion
• I am a maintainer / this is internal Roomote work

What changed

When a linked pull request is merged or closed, Roomote now writes that terminal status into the owning task's transcript history as an out-of-band assistant message — the same resurfacing mechanism already used for PR review-feedback notifications.

• Adds PR_STATUS_NOTIFICATION_TASK_MESSAGE_SOURCE to the out-of-band message sources so the next agent turn can re-surface the change.
• Adds recordPrStatusChangeInTaskHistory in the SDK with Redis per-task dedup against webhook retries.
• Uses wall-clock timestamps so two terminal PR events in the same second cannot collide on the task-message unique key.
• Formats GitLab (!n) and Azure DevOps (PR n) references with provider-native shorthand.
• Hooks the recorder into terminal PR lifecycle paths for GitHub, GitLab, Gitea, Bitbucket, and Azure DevOps.

Existing platform merge chat notifications are unchanged; this path only fills the agent-context gap for status in task history.

How it was tested

• Unit tests for the new status recorder (record-pr-status-change.test.ts), including provider reference formatting and wall-clock timestamps
• Existing webhook handler tests for GitHub, GitLab, Gitea, and ADO (mock wiring updated)
• Out-of-band claim tests remain green (new source is registered in the shared source list)
• Pre-push lint:fast, check-types:fast, and knip passed on push

Checklist

• The PR title follows the repo convention: [Fix], [Feat], [Improve], [Refactor], [Docs], or [Chore] followed by a user-facing description
• This PR is small and scoped to one change
• pnpm lint and pnpm check-types pass locally
• I added tests or included a clear manual validation note above
• I removed secrets, tokens, private keys, and customer data from code, logs, and screenshots
• If this change should appear in the changelog, I ran pnpm changeset

[roomote-roomote]

No new code issues found. Both earlier findings are resolved in 9ad7420. See task

• Event-time ts can overwrite an earlier status line — fixed: status messages now use Date.now() so concurrent terminal events cannot collide on the (taskId, protocol, ts, eventType) unique key; webhook retries stay idempotent via the Redis claim.
• # reference is provider-inaccurate for GitLab/ADO — fixed: formatter now uses # for GitHub/Gitea/Bitbucket, ! for GitLab, and PR n for Azure DevOps.

_{Reviewed 9ad7420}

[roomote-roomote]

Fixed both open review findings in 9ad7420:

1. Status-history messages now use Date.now() so two PR terminal events in the same second no longer can overwrite each other on the task-message unique key.
2. GitLab uses !n and Azure DevOps uses PR n in the agent-facing status text (GitHub/Gitea/Bitbucket keep #n).

Tests updated/passed for the recorder.