fix(quick-chat): auto-select default model, fix new-chat button contrast, autofocus input

- Pre-select the global default (or first available) model on first open so
  users can chat without manually picking from the dropdown.
- Bump specificity of the new-chat (+) button styles so the CTA bg/text
  applies instead of being overridden by the header's .btn-icon rule.
- Focus the message input on panel open via rAF.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

packages/dashboard/app/components/QuickChatFAB.css

@@ -258,19 +258,23 @@
   white-space: nowrap;
 }
 
-.quick-chat-new-chat-btn {
+.quick-chat-panel-header-actions .btn-icon.quick-chat-new-chat-btn {
   background: var(--cta-bg);
-  border: 1px solid var(--cta-border);
+  border-color: var(--cta-border);
   color: var(--cta-text);
 }
 
-.quick-chat-new-chat-btn:hover {
+.quick-chat-panel-header-actions .btn-icon.quick-chat-new-chat-btn:hover {
   background: var(--cta-bg-hover);
+  border-color: var(--cta-border-hover);
+  color: var(--cta-text);
 }
 
-.quick-chat-new-chat-btn:disabled,
-.quick-chat-new-chat-btn:disabled:hover {
+.quick-chat-panel-header-actions .btn-icon.quick-chat-new-chat-btn:disabled,
+.quick-chat-panel-header-actions .btn-icon.quick-chat-new-chat-btn:disabled:hover {
   background: var(--cta-bg);
+  border-color: var(--cta-border);
+  color: var(--cta-text);
   opacity: 0.6;
   cursor: not-allowed;
 }

packages/dashboard/app/components/QuickChatFAB.tsx

@@ -871,17 +871,18 @@ export function QuickChatFAB({
           );
           if (hasDefaultModel) {
             setSelectedModel(defaultSelection);
-            setChatMode("model");
+            if (agents.length === 0) {
+              setChatMode("model");
+            }
             return;
           }
         }
 
-        // Fallback: auto-select first model only when no agents exist.
-        if (agents.length === 0) {
-          const firstModel = loadedModels[0];
-          if (firstModel) {
-            setSelectedModel(`${firstModel.provider}/${firstModel.id}`);
-          }
+        // Always pre-select the first model so users can start chatting in model mode
+        // without having to manually pick from the dropdown.
+        const firstModel = loadedModels[0];
+        if (firstModel) {
+          setSelectedModel(`${firstModel.provider}/${firstModel.id}`);
         }
       })
       .catch((error: unknown) => {
@@ -955,6 +956,14 @@ export function QuickChatFAB({
     pendingAttachmentsRef.current = pendingAttachments;
   }, [pendingAttachments]);
 
+  useEffect(() => {
+    if (!isOpen) return;
+    const frame = requestAnimationFrame(() => {
+      inputRef.current?.focus();
+    });
+    return () => cancelAnimationFrame(frame);
+  }, [isOpen]);
+
   // Attachment object URLs must be revoked when the composer unmounts.
   useEffect(() => {
     return () => {