fix(daemon): Fix double-unlock risk in debouncer on action panic (#1140)

The debouncer's timer callback used a pattern that could cause a
double-unlock panic if the action function panicked:

  d.mu.Lock()
  defer d.mu.Unlock()
  if d.seq == currentSeq {
      d.mu.Unlock()  // Manual unlock
      d.action()     // If this panics...
      d.mu.Lock()    // ...this never runs
  }                  // ...but defer still tries to unlock

Fix: Remove the defer and manually manage lock state. Now if the
action panics, the lock is already released, preventing a
double-unlock panic that would mask the original panic.

Co-authored-by: Steven Syrek <steven.syrek@deepl.com>
Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

cmd/bd/daemon_debouncer.go

@@ -41,15 +41,18 @@ func (d *Debouncer) Trigger() {
 
 	d.timer = time.AfterFunc(d.duration, func() {
 		d.mu.Lock()
-		defer d.mu.Unlock()
-
 		// Only fire if this is still the latest trigger
-		if d.seq == currentSeq {
-			d.timer = nil
-			d.mu.Unlock() // Unlock before calling action to avoid holding lock during callback
-			d.action()
-			d.mu.Lock() // Re-lock for defer
+		if d.seq != currentSeq {
+			d.mu.Unlock()
+			return
 		}
+		d.timer = nil
+		d.mu.Unlock() // Unlock before calling action to avoid holding lock during callback
+
+		// Action runs without lock held. If action panics, the lock is already
+		// released, avoiding a double-unlock that would occur with the previous
+		// defer-based pattern.
+		d.action()
 	})
 }