Drive provider filters from the archive dataset

CURRENT.md

@@ -40,6 +40,13 @@ mobile draft at 390px.
   - [x] C11 preview caching: Discord-hosted image/GIF previews (WebP 320px, hash-addressed, 5 MiB
     cap, one attempt) run after every walk in both modes. Live run `...-20260916090722`:
     `previewed: 2`; thumbs served over `/api/media/<scrape>/<item>/thumb` (200).
+  - [x] C47 Provider list from the dataset. Aggregated the `provider` column over all 11 scraper
+    databases (distinct URLs): discord 13631 (folding cdn.discordapp.com and media.discordapp.net),
+    youtube 4840, tenor 352, twitch 196, twitter 111, steam 83, medal 59, sketchfab 31, gfycat 30,
+    imgur 23. Those ten now live in `PROVIDER_FILTERS` (media-scrape), are served in
+    `/api/media/status` as `providerFilters`, and the Advanced drawer renders the source checkboxes
+    from that list (4chan stays out; the default URL host exclusion covers it). Unit test for the
+    list shape and a smoke check that the checkbox count matches the API list (13 = 10 + 3 kinds).
   - [x] C46 Sort and exclusion filters. The Advanced drawer gained a sort select (newest, oldest,
     user, size, length; global over the merged URL-dedupe stream) and a **Do not include** group
     with nested collapsibles: sources (Twitch, YouTube, Discord, Tenor, Giphy, embeds, attachments,