- Simplify flows.zh-CN.md to an entry + quick reference, add "Quick Navigation" and in-depth reading links, original sections 6/7/9/10 are retained in the entry page with titles but changed to links.
- Add in-depth reading sub-document:
- docs/ai-playbook/flows/frontend.zh-CN.md
- docs/ai-playbook/flows/backpressure-chunking.zh-CN.md
- docs/ai-playbook/flows/resume.zh-CN.md
- docs/ai-playbook/flows/reconnect-consistency.zh-CN.md
- docs/ai-playbook/index.zh-CN.md add "Process (In-depth reading split)" index
- Prevent server-side exceptions (Application error) on mobile after redirects
- useOneShotSlowHint: guard document; use global setTimeout; conditionally attach visibilitychange
- useConnectionFeedback: guard document.visibilityState; register/remove listeners only on client
- usePageSetup: guard window before tracking referrer and parsing roomId
- tracking: early return when window is undefined
- docs(flows): add “SSR & DOM access guard (must-read)” checklist; renumber next section
- 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