Refresh linked PR state when an agent finishes to avoid temporary sidebar movement

[lexidor]

When an agent closes its own PR as its final action, the thread moves from Working to Pending for about a minute before moving to Settled. This temporary sidebar movement draws attention to a thread that is already finished.

In T3 0.0.45, linked PRs refresh once a minute, and PR reads have a 60-second cache. Two recent examples took 51 and 59 seconds from PR closure to thread settlement.

Could T3 refresh linked PR state when an agent finishes, bypassing the cache, before deciding where the thread belongs? That would let completed threads move directly from Working to Settled when their PR is already closed.

Relevant implementation:

• PullRequestSyncReactor.ts: one-minute refresh loop
• PullRequestReadCache.ts: 60-second read cache
• ThreadSettlementReactor.ts: settlement triggered by refreshed PR state

[lexidor]

If this annoys you to, tell your agent:

We changed what happens when an agent finishes its turn:

- Keep the thread in **Working** while immediately refreshing its linked PRs.
- If the PRs are closed or merged and the thread qualifies for auto-settlement, move it directly to **Settled**, avoiding the brief appearance in Pending.
- Wait at most five seconds. If refreshing fails or takes longer, finish normally and let the existing poller handle settlement.

This runs entirely on the server. The client and polling interval are unchanged.