docs(user): reader audio section + kobo guide refresh to platform reality

reader-guide.md gains the audiobook/episode player section (seek,
prev/next episode, Bookmarks panel, Chapters list, Player settings with
autoplay/speed/resume-rewind overrides, Shortcuts dialog) — the player
existed with zero user docs.

kobo-setup.md drops the stale 'not available yet, actively being
developed' framing: the server side of native Kobo sync is implemented
and documented (sync/initialization endpoints, bookmark + markup sync,
shelf mappings, KEPUB sidecar config), so the guide now states exactly
that, keeps stock-firmware rollout as the honest remaining piece, and
keeps KOReader as the supported today-path.

ui-controls.md: Player settings / Shortcuts & interactions / Chapters /
Bookmarks entries (templ-entity fragments for ampersand labels).

docs/user/devices/kobo-setup.md

@@ -1,34 +1,41 @@
 # Kobo Device Setup Guide
 
-> ## 🚧 Coming Soon
->
-> Native Kobo sync is not available yet. It is actively being developed and this guide will be filled in as the feature lands.
+There are two ways to use a Kobo with Bookhoard, and they can be chosen
+independently per device:
 
-## Using a Kobo With Bookhoard Today
+| Way | Status | What you get |
+| --- | --- | --- |
+| **KOReader on the Kobo** | Works today, fully | Reading position, bookmarks, highlights, notes, OPDS wireless book delivery |
+| **Stock Kobo firmware (native sync)** | Server support is complete; device-side enablement is the remaining piece | Reading position and stats, bookmarks/highlights/notes, shelf mappings (your collections as Kobo shelves), automatic EPUB → KEPUB conversion, and the Kobo's own sync experience |
 
-You don't have to wait: **KOReader runs on Kobo hardware** and syncs fully with Bookhoard today — reading position, bookmarks, highlights, and notes, plus OPDS wireless book delivery.
+## Using a Kobo today
 
-See the **[KOReader Setup Guide](koreader-setup.md)** for complete instructions.
+**KOReader runs on Kobo hardware** and syncs fully with Bookhoard right
+now — the [KOReader Setup Guide](koreader-setup.md) walks the whole path
+(plugin install, server approval, OPDS delivery, troubleshooting).
 
-## What's Planned for Native Kobo Sync
+## About native Kobo sync
 
-When released, native Kobo sync will let stock Kobo firmware talk directly to Bookhoard:
+The server side of the native protocol is implemented and documented: the
+Kobo sync and initialization endpoints, bookmark and markup (highlight and
+note) sync, shelf mappings that expose your collections as Kobo shelves,
+and the KEPUB sidecar configuration used for conversion. What remains is
+the device-side rollout, so stock-firmware sync is not yet something to
+rely on for daily use — this guide will gain a full setup walkthrough when
+that lands.
 
-- **Reading position sync** — percentages, pages, and reading statistics
-- **Bookmarks, highlights, and notes** — synced with the web and other devices
-- **OPDS wireless delivery** — browse and download books directly on the Kobo
-- **Automatic EPUB → KEPUB conversion** — for better Kobo rendering
-- **Shelf mappings** — Bookhoard collections appearing as Kobo shelves
-
-The server-side protocol endpoints are already implemented and under test; the feature will be announced when it's ready for real devices.
+Nothing about native sync takes anything away from KOReader: the two can
+coexist, and a KOReader setup keeps working either way.
 
 ## FAQ
 
 **Q: Should I buy a Kobo to use with Bookhoard today?**
-A: Kobo devices work great with Bookhoard via KOReader. Native (stock firmware) sync is coming soon.
+A: Yes, via KOReader — it is the supported path today and covers sync plus
+wireless book delivery.
 
-**Q: What happens to my KOReader setup when native sync arrives?**
-A: Nothing — KOReader will keep working. Native sync simply adds another option for people who prefer stock Kobo firmware.
+**Q: Will I have to redo anything when native sync lands?**
+A: No — KOReader keeps working; native sync just adds the stock-firmware
+option.
 
 ## Additional Resources