fix(photos): fix SQL type mismatch, pagination panic, missing icons, and add day/month/year grouping

- Fix photos endpoint 500: remove ::uuid cast on user_id WHERE clause (VARCHAR column)
- Fix pagination underflow panic when total_pages is 0
- Add missing 'images' and 'play' icons to SVG icon registry
- Add day/month/year grouping toggle with localStorage persistence
- Improve grid spacing and group header styling per mode
- Add i18n translations for grouping labels (all 9 locales)

static/locales/es.json

@@ -14,7 +14,10 @@
   "photos": {
     "empty_state": "Aún no hay fotos",
     "empty_hint": "Sube imágenes o videos para verlos aquí",
-    "items_selected": "seleccionados"
+    "items_selected": "seleccionados",
+    "view_daily": "Día",
+    "view_monthly": "Mes",
+    "view_yearly": "Año"
   },
   "share": {
     "dialogTitle": "Compartir Enlace",