feat(FN-3603): improve mobile chat with jump-to-latest and bubble width fix

This merge implements FN-3603, adding jump-to-latest controls for the chat view and improving mobile bubble width layout, with corresponding CSS updates in ChatView and QuickChatFAB components. It also includes documentation for the new mobile chat controls, a fix for workspace lint regex escaping,

Fusion-Task-Id: FN-3603

docs/dashboard-guide.md

@@ -47,6 +47,8 @@ Chat view provides project-scoped conversations with agents.
 - Entering `/clear` (exact match after trimming) in the composer starts a fresh thread for the current chat target instead of sending the literal command to the model
 - On mobile, the New Chat and Delete Conversation dialogs use a compact inset treatment (centered, viewport-bounded, internally scrollable) instead of the app's default full-height mobile modal chrome.
 - Full Chat and Quick Chat both consume the same streamed `/api/chat/sessions/:id/messages` response contract, and both now prefer the authoritative assistant `message` snapshot on `done` while still accumulating `text` chunks when present (so providers without incremental text streaming still render output immediately)
+- Chat message lists now track near-bottom scroll state: while you are reading older messages, live streaming/new replies do not force-scroll; a **Latest** jump control appears until you return to the tail.
+- On mobile (`max-width: 768px`), chat bubbles are slightly wider in full Chat for improved readability while preserving header/composer gutters.
 
 ![Chat view](./screenshots/chat-view.png)
 
@@ -67,6 +69,8 @@ Quick Chat is an optional floating panel for fast, project-scoped assistant conv
 - Tool-call summaries in the floating quick-chat panel are intentionally condensed into a single-line header row (especially on small screens) so tool name + status stay scannable without multi-line wrapping
 - On mobile viewports, opening Quick Chat auto-focuses the composer as soon as it is ready so the keyboard opens immediately
 - FAB dragging uses pointer events with document-level move/up tracking and a 5px drag threshold so Android touch drags reposition reliably while short taps still open Quick Chat
+- Quick Chat now mirrors full Chat tail behavior: if you scroll up, live updates stop auto-following and a **Latest** jump control appears until you jump back down.
+- On mobile, Quick Chat bubbles are slightly wider while keeping compact tool-call summary layout and full-screen/safe-area behavior intact.
 
 ## Mailbox View