docs: headline session tabs instead of the auth-expiry fix

CHANGELOG.md

@@ -6,9 +6,8 @@ All notable changes to this project will be documented in this file.
 
 - **Chat scrolling rebuilt around your message.** Sending parks your message near the top and the reply streams into the space below it, so you read from where you asked instead of chasing the bottom. Streamed text arrives a paragraph at a time with a soft fade and the view glides after it in one motion; scrolling up immediately hands you the wheel, with the scroll-to-bottom pill carrying the model's working status while you're away. Opening a session lands on the newest message with no animation.
 - **Keyboard shortcuts redesigned** (thanks @ChangeHow for the registry): one model everywhere — single chords for everyday actions, a two-step Cmd/Ctrl+K leader for open/go actions (P project picker, G branch picker, L session list, T timeline, R rename session, N prompt navigator, I services, C theme, H help), held Cmd/Ctrl+digit for session tabs and held Cmd/Ctrl+Option+digit for panel surfaces. Cmd/Ctrl+B toggles the sidebar, rare actions moved into the command palette, and every tooltip shows the binding you actually have set. Shortcuts no longer require an English keyboard layout — bindings follow the physical key, including when recording custom ones. Custom bindings from the old layout reset once.
-- **Session expiry is announced, not discovered.** When the OpenChamber login expires (LAN browser, paired device, tunnel), a banner appears under the header within seconds — before anything is clicked — with a Log in button that opens the usual unlock screen. Work stays visible, sending pauses until login, a failed send always returns the typed prompt to the input, and a conversation that failed to load while logged out explains that and reloads itself after login. A 401 is confirmed against the server first, so an expired model-provider key can't fake a logout.
 - **Chat context attachments:** everything you attach to a message — diff/file/plan comments, terminal selections, browser annotations, PR comments and failed checks, linked issues and PRs — now shows up as a compact context card: a source header, the captured content behind an expander, and your comment below it, instead of a wall of raw text.
-- Session tabs (opt-in): the web/desktop header can show open sessions as browser-style tabs (Settings → General → Navigation). Clicking a tab switches the whole workspace, closing one (×, middle-click, or Alt+W) never touches the session itself, tabs reorder by drag, carry the running/unread dot, and hold the full session menu including rename-in-place.
+- **Session tabs (opt-in):** the web/desktop header can show open sessions as browser-style tabs (Settings → General → Navigation). Clicking a tab switches the whole workspace, closing one (×, middle-click, or Alt+W) never touches the session itself, tabs reorder by drag, carry the running/unread dot, and hold the full session menu including rename-in-place.
 - Faster session switching in large workspaces (thanks @c-w-xiaohei): the sidebar no longer rebuilds on switch and recently viewed sessions restore their rendered messages; end-to-end switch time roughly halved with thousands of loaded sessions.
 - Permission cards answer to the keyboard: Alt+Enter allows once, Alt+Shift+Enter allows always, Alt+Backspace denies — the keys are printed on the buttons. The auto-accept toggle got Cmd/Ctrl+K, A.
 - Sessions: Cmd/Ctrl+Alt+Left/Right steps back and forward through the sessions you opened in this window, browser-history style; with session tabs enabled it moves between neighbouring tabs instead.
@@ -24,6 +23,7 @@ All notable changes to this project will be documented in this file.
 - Chat: a "Follow new content while streaming" checkbox (Settings → Chat → Streaming, on by default) turns automatic following off entirely; with it off, the scroll-to-bottom pill now appears as soon as the reply grows past the visible area.
 - Command palette: rarely used commands (pin session, copy session ID, multi-run launcher, archived sessions, notes, todos, status, theme) are found by typing but stay off the first screen.
 - Mobile: narrowing a browser window past phone size switches into the mobile layout (and back when widened); the old/new mobile layout setting is gone.
+- Auth: an expired OpenChamber login (LAN browser, paired device, tunnel) is announced within seconds by a banner under the header with a Log in button — instead of being discovered through failing actions. Work stays visible, sending pauses until login, a conversation that failed to load while logged out reloads itself after login, and an expired model-provider key can't fake a logout.
 - Chat: a failed send returns your typed prompt to the input — whatever the reason — instead of losing it to an error toast; a mid-send session switch lands it in that session's draft.
 - Chat: opening a session or resizing panels could strand the view in a large empty space below the last message; the list now returns to the real end, and a width resize keeps a reader who was at the bottom at the bottom.
 - Chat: prompt-rail and message jumps land exactly on the target once the layout finishes measuring, and clicking the last rail item always works.