feat(gif): favourites and category shortcuts

Favourites are stored server-side per user, so one made on the phone is there
on the desktop — the point of favouriting. The whole result is stored rather
than an id: the provider offers no lookup by id, so an id-only favourite could
not be rendered without re-finding it through search.

Category chips translate their label but not their query, which goes to a
provider that indexes in English.

The star sits beside the tile button rather than inside it: a button within a
button is invalid and swallows the click. Toggling is optimistic and reverts
on failure, and favourites skip both the loading skeleton and the infinite
scroll, which belong to provider-backed browsing only.

Server caps favourites per user and rejects non-http(s) URLs, which become
<img src> in everyone's picker.

packages/server/drizzle/meta/_journal.json

@@ -85,6 +85,13 @@
       "when": 1788190305853,
       "tag": "0011_lethal_bruce_banner",
       "breakpoints": true
+    },
+    {
+      "idx": 12,
+      "version": "6",
+      "when": 1788192490711,
+      "tag": "0012_sour_pixie",
+      "breakpoints": true
     }
   ]
 }