Rebuild on file renames so deletes take effect

The watcher only reacted to Create/Write/Remove. A /manage delete moves the
image and sidecar into content/.trash/, which on Linux arrives as a Rename
(inotify IN_MOVED_FROM), not a Remove — so the watcher never fired and the
delete left the published site unchanged (uploads worked because they Create
and Write). Watch Rename too, which also covers removing a photo with a manual
mv. The delete handler still triggers its own immediate rebuild; this makes the
watcher path agree with it.

watcher.go

@@ -30,6 +30,12 @@ func NewWatcher(dir string, g *Generator) (*Watcher, error) {
 // Watch blocks, watching for changes and triggering rebuilds.
 // Rapid events (e.g. scp writing an image then its sidecar) are debounced
 // with a 500 ms window so only one rebuild fires per logical upload.
+//
+// Rename is watched alongside Create/Write/Remove: moving a photo out of the
+// content directory — which is exactly what a /manage delete does when it
+// sends files to content/.trash/ — arrives as a Rename (inotify IN_MOVED_FROM)
+// on Linux, not a Remove, so without it a delete (or a manual mv) would leave
+// the site unrebuilt.
 func (w *Watcher) Watch() {
 	var timer *time.Timer
 	rebuild := func() {
@@ -47,7 +53,8 @@ func (w *Watcher) Watch() {
 			if !isRelevant(event.Name) {
 				continue
 			}
-			if event.Has(fsnotify.Create) || event.Has(fsnotify.Write) || event.Has(fsnotify.Remove) {
+			if event.Has(fsnotify.Create) || event.Has(fsnotify.Write) ||
+				event.Has(fsnotify.Remove) || event.Has(fsnotify.Rename) {
 				if timer != nil {
 					timer.Stop()
 				}