docs: document P4-3 (knock admin badge) and P5-11 (AFK auto-mute)

- LOTUS_FEATURES.md: added sections for Knock-to-Join Notifications for
  Admins and AFK Auto-Mute in Voice under their parent headings
- LOTUS_TODO.md: marked P4-3 and P5-11 as [x] completed
- README.md: updated Calls & Voice bullet list with AFK auto-mute entry;
  expanded knock admin badge entry with badge-count detail

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

README.md

@@ -49,6 +49,7 @@ The Lotus Chat logo (`lotus_chat.png`) is a derivative work based on the origina
 - Your chat background shows through the call view
 - Dark/light mode inside calls matches your Lotus Chat theme
 - Calls are available in DMs and private groups only — no accidental mass rings
+- AFK auto-mute: mic is automatically silenced after a configurable idle timeout (1–30 min); a toast confirms the action
 
 ### Customization & Appearance
 
@@ -102,7 +103,7 @@ The Lotus Chat logo (`lotus_chat.png`) is a derivative work based on the origina
 - Knock-to-join: request access to a room; admins approve or deny from the members list
 - Media gallery drawer: browse all images, videos, and files shared in a room
 - Invite link and QR code in room settings
-- Pending knock requests shown in the members list for room admins
+- Pending knock requests shown in the members list for room admins with a live badge count on the Members button
 - Homeserver support contact displayed in Help & About (MSC1929)
 - Server notice rooms are visually distinct from regular DMs