- Receiver: auto-fill and join on Retrieve tab when input empty, not in room, no URL roomId, and cachedId exists (ClipboardApp + roomIdCache)
- Sender: “Use cached ID” now immediately joins the room (add onUseCached + disabled to CachedIdActionButton; wire in SendTabPanel)
- UI: add ThemeToggle and integrate into Header (desktop and mobile)
- Styles: replace hardcoded white with design tokens in Retrieve panel (bg-card/text-card-foreground) for dark mode
- Docs: update AI playbook flows and code-map
- Attempt reconnection on 'disconnected' | 'failed' | 'closed' states (BaseWebRTC)
- Relax gating: rejoin when roomId exists and any of isPeerDisconnected, isSocketDisconnected, or socketId changed
- Auto re-join room on socket 'connect' if lastJoinedSocketId differs or not in room; send initiator-online for initiators
- Track lastJoinedSocketId after successful join and reset isInRoom when socketId changes to bypass early-return
- Update flows to document mobile background/foreground reconnection and socketId-based rejoin