docs(daemon): update comment to reflect self-cleaning model

The comment incorrectly referred to polecats without hooked work as "idle".
With the self-cleaning model, polecats self-nuke on completion - there are
no idle polecats. A polecat without work is orphaned (needs cleanup).

Closes: gt-0jn0k

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

internal/daemon/daemon.go

@@ -745,7 +745,10 @@ func (d *Daemon) checkPolecatHealth(rigName, polecatName string) {
 
 	// Check if polecat has hooked work
 	if info.HookBead == "" {
-		// No hooked work - no need to restart (polecat was idle)
+		// No hooked work - this polecat is orphaned (should have self-nuked).
+		// Self-cleaning model: polecats nuke themselves on completion.
+		// An orphan with a dead session doesn't need restart - it needs cleanup.
+		// Let the Witness handle orphan detection/cleanup during patrol.
 		return
 	}