Add sort and exclusion filters to the media grid

CURRENT.md

@@ -40,6 +40,15 @@ 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] 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,
+    stickers), file types, size (less/greater than with B/KB/MB/GB units), and length (seconds).
+    Store, `/api/media` + `/api/media/stats` (shared parser), and MCP `query_media` all carry the
+    new params; size and length ranges drop rows with unknown values, and the ext matching now
+    coalesces NULL content types so a `NOT (...)` cannot swallow rows. Also hid the media filter bar
+    and drawer on the Bot tab. Unit tests for every exclusion, all five sorts (nulls last), and
+    smoke checks for the hidden bar on the Bot tab.
   - [x] C45 Streaming media grid. The grid rebuilt every card on each appended page, which made
     filtered browsing flash, and the `Load more` trigger only worked once the grid could already
     scroll, so short filtered pages dead-stopped at ~11 cards. Now pages append incrementally