## Summary
Added auto-archive functionality to the PR monitor service in `crates/services/src/services/pr_monitor.rs`.
**Change:** When the PR monitor detects a PR has been merged (via polling every 60 seconds), it now archives the workspace automatically (unless the workspace is pinned).
**Code added (lines 128-131):**
```rust
// Archive workspace unless pinned
if !workspace.pinned {
Workspace::set_archived(&self.db.pool, workspace.id, true).await?;
}
```
This makes the PR monitor behavior consistent with the other two merge paths:
- Direct merge (already archives)
- Attaching an already-merged PR (already archives)
- PR monitor detecting merge (now archives too)
9f1c4b9416