fix: add tags optimistically on the detail page

submitTag now shows the chip immediately with the typed name and reconciles
it with the server's (normalized) ref on success, rolling back on error —
matching the already-optimistic tag removal instead of blocking on the
round-trip.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

frontend/package.json

@@ -1,6 +1,6 @@
 {
   "name": "mangalord-frontend",
-  "version": "0.118.0",
+  "version": "0.118.1",
   "private": true,
   "type": "module",
   "scripts": {