refactor: queue primitive, tool status badges, and tool display cleanup

- Add Queue/QueueItem/QueueItemIndicator/QueueItemContent primitive
- Rewrite TodoList using Queue (clean list, no bordered cards, no priority badges)
- Add ToolStatusBadge component (Running/Completed/Error/Denied)
- Migrate CollapsibleSection from native <details> to Collapsible primitive
- Add badge prop threading through CollapsibleDisplay and CollapsibleSection
- Add status badges to OneLineDisplay and CollapsibleDisplay via ToolRenderer
- Update SubagentContainer: theme tokens + Collapsible for tool history
- Replace hardcoded gray-* colors with theme tokens throughout tool displays

src/components/chat/view/subcomponents/ChatComposer.tsx

@@ -98,7 +98,6 @@ interface ChatComposerProps {
   onTextareaScrollSync: (target: HTMLTextAreaElement) => void;
   onTextareaInput: (event: FormEvent<HTMLTextAreaElement>) => void;
   onInputFocusChange?: (focused: boolean) => void;
-  isInputFocused?: boolean;
   placeholder: string;
   isTextareaExpanded: boolean;
   sendByCtrlEnter?: boolean;
@@ -154,7 +153,6 @@ export default function ChatComposer({
   onTextareaScrollSync,
   onTextareaInput,
   onInputFocusChange,
-  isInputFocused,
   placeholder,
   isTextareaExpanded,
   sendByCtrlEnter,
@@ -175,13 +173,8 @@ export default function ChatComposer({
   // Hide the thinking/status bar while any permission request is pending
   const hasPendingPermissions = pendingPermissionRequests.length > 0;
 
-  // On mobile, when input is focused, float the input box at the bottom
-  const mobileFloatingClass = isInputFocused
-    ? 'max-sm:fixed max-sm:bottom-0 max-sm:left-0 max-sm:right-0 max-sm:z-50 max-sm:bg-background max-sm:shadow-[0_-4px_20px_rgba(0,0,0,0.15)]'
-    : '';
-
   return (
-    <div className={`flex-shrink-0 p-2 pb-2 sm:p-4 sm:pb-4 md:p-4 md:pb-6 ${mobileFloatingClass}`}>
+    <div className="flex-shrink-0 p-2 pb-2 sm:p-4 sm:pb-4 md:p-4 md:pb-6">
       {!hasPendingPermissions && (
         <ClaudeStatus
           status={claudeStatus}