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

packages/dashboard/app/components/ChatView.css

@@ -214,6 +214,7 @@
   flex-direction: column;
   min-width: 0;
   min-height: 0;
+  position: relative;
 }
 
 .chat-thread-header {
@@ -284,6 +285,14 @@
   word-break: break-word;
 }
 
+.chat-jump-to-latest {
+  position: absolute;
+  left: 50%;
+  bottom: calc(var(--space-xl) * 3);
+  transform: translateX(-50%);
+  z-index: 2;
+}
+
 .chat-message--user {
   align-self: flex-end;
   background: var(--accent);
@@ -1122,4 +1131,12 @@
     width: calc(var(--space-lg) * 2.25);
     height: calc(var(--space-lg) * 2.25);
   }
+
+  .chat-message {
+    max-width: 82%;
+  }
+
+  .chat-jump-to-latest {
+    bottom: calc(var(--space-xl) * 4);
+  }
 }