feat(workspace,settings): model menu chip in the composer, compact settings panels

The workspace home's composer takes ONE Model chip (ModelMenu: model list
plus Effort) and moves AI Router / Permission / Local-New worktree into the
row under it; Settings drops the General-page cost card and export row,
PricingSettings and the empty states are compacted for settings panels.

client/src/components/EmptyState.tsx

@@ -75,20 +75,26 @@ export interface EmptyStateProps {
   description: string;
   /** Optional CTA rendered below the description (button, link, or form). */
   action?: React.ReactNode;
+  /** Inside a card (a settings panel) rather than a whole page: less padding. */
+  compact?: boolean;
 }
 
 /**
  * Renders a vertically centered empty state inside the main content column.
  * @param props See {@link EmptyStateProps}.
  */
-export function EmptyState({ icon: Icon, title, description, action }: EmptyStateProps) {
+export function EmptyState({ icon: Icon, title, description, action, compact }: EmptyStateProps) {
   return (
-    <div className="flex flex-col items-center justify-center py-20 text-center">
-      <div className="w-14 h-14 rounded-2xl bg-surface-4 flex items-center justify-center mb-5">
+    <div
+      className={`flex flex-col items-center justify-center text-center ${compact ? "py-8" : "py-20"}`}
+    >
+      <div
+        className={`rounded-2xl bg-surface-4 flex items-center justify-center ${compact ? "w-10 h-10 mb-3" : "w-14 h-14 mb-5"}`}
+      >
         <Icon className="w-6 h-6 text-fg-muted" />
       </div>
       <h3 className="text-base font-medium text-fg-secondary mb-2">{title}</h3>
-      <p className="text-sm text-fg-muted max-w-md mb-6">{description}</p>
+      <p className={`text-sm text-fg-muted max-w-md ${compact ? "" : "mb-6"}`}>{description}</p>
       {action}
     </div>
   );