Add the Bot-tab backfill control room and media strip rules

CURRENT.md

@@ -40,6 +40,20 @@ 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] C43 Bot-tab backfill control room and media-tab strip rules. The engine gained
+    `previewBatch`/`rateLimitStatus`/`updateOptions`; a new `BackfillQueue` groups preview work per
+    chat (paused and resumed scrapes of a chat combine), runs one job at a time in batches, and
+    reports pending/cached/failed per kind, throughput, measured and settings-based ETA, and the
+    live cooldown. `MediaService` drives it and exposes `GET /api/media/backfill` plus start/pause;
+    `/api/preferences` now carries `media.tunables` (Backfilling / Scraping / Timers, persisted and
+    applied live). The Bot tab shows totals with a Bot/Puppet split, per-chat job cards with
+    progress and Start/Pause, **Start backfill** / **Pause all**, the red `API timed out, increase
+    timers` banner, and the three settings groups. The media strip shows running plus one paused
+    scrape, dismisses a paused one on Stop without stopping it, turns red while limited, and shows
+    a session-only `N scrapes completed` note. The old `VESKSLOP_MEDIA_*` tuning env vars are gone.
+    New unit tests cover batching, the cooldown, live retuning, and queue grouping/finish/pause;
+    the Playwright smoke test covers the Bot tab. Live: daemon restarted, 6018 pending / 13321
+    cached / 652 failed, ETA 4h 7m at 21.4 rows/min, settings round-trip verified.
   - [x] C42 Preview attempts cap. The restart log showed the backfill retrying dead hosts (Gfycat
     DNS is gone, Streamable answers 400) forever as "transient". Rows now carry
     `preview_attempts`; after `VESKSLOP_MEDIA_PREVIEW_MAX_ATTEMPTS` (3) the row is marked