docs: producer & media ingest, ops changes, library updates (October 2026)

- engineering-guide §10: media attachments, alt-text delivery, producer,
  audio-less silence bed, chunked ingest, upload caps
- admin-guide §10: oCIS retired from the payload path, storage_key (041),
  publishing media resolver + dedupe origins, produce-worker, api restart
  rate-limit note; §6.3 marked legacy
- user-guide §9: 2 GiB Library uploads, compose attachments + alt text,
  producer, chunked large-video uploads

docs/user-guide.md

@@ -59,7 +59,14 @@ Each account card shows: platform, handle, **capability chips** (what this conne
 
 Every meaningful action (post published, role changed, connection added, credential rotated, approval granted…) is recorded in a **tamper-evident hash chain**. Filter by actor or action; click a row to open the **diff viewer** — what changed, field by field, with removed/added values. Secret values always show as `[REDACTED]`: keys and tokens are never written into the audit log, by construction. Export to CSV for compliance.
 
-## 9. What's real vs. coming
+## 9. New in the Library & Publishing
+
+- **Library (Files) tab:** upload up to **2 GiB per file**. Files are encrypted and stored in the hub's own object storage. The old 20 MiB limit and the separate Drive tab are gone — the Library replaces both.
+- **Compose:** attach up to **4 images or videos** per post (10 MiB per image, 64 MiB per video) and add **alt text** descriptions — they appear on Mastodon.
+- **Video producer:** apply **lower-third, logo, or clock overlays** and **voiceover** to any library video. Clips with no audio get a synthesized silence bed, so they always work. Results land back in the library and can be published like any other asset.
+- **Large videos:** uploads are automatically split into 10 MB chunks — big files work even through Cloudflare.
+
+## 10. What's real vs. coming
 
 **Now (Level 1):** monitoring streams, compose with previews, approvals, scheduling, publishing pipeline, encrypted credential vault, audit trail. *(The screens currently run on representative sample data while the backend wiring lands.)*
 
@@ -68,7 +75,7 @@ Every meaningful action (post published, role changed, connection added, credent
 - **Crosspost** — one action moves content across platforms with your commentary (an Instagram image quoted into Mastodon, a Mastodon video into Facebook), flowing through approvals.
 - **Level 2** — video uploads, livestreams, the Virtual Channel / Auto Director master-control system, and the operator Control Room.
 
-## 10. FAQ
+## 11. FAQ
 
 **Why can't I retweet on some columns?** That platform's API doesn't expose resharing. We render only real capabilities.