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/pages/SettingsHub.tsx

@@ -52,8 +52,6 @@ interface Section {
   title: string;
   description: string;
   Icon: ComponentType<{ className?: string }>;
-  /** Full content width (config editors and tables), else `max-w-3xl`. */
-  wide?: boolean;
   render: () => ReactNode;
 }
 
@@ -119,7 +117,6 @@ export function SettingsHub() {
       id: "agents",
       group: "agents",
       Icon: Bot,
-      wide: true,
       ...s("agents"),
       render: () => <AiToolsSettings />,
     },
@@ -129,7 +126,6 @@ export function SettingsHub() {
             id: "agents/claude-code",
             group: "agents" as const,
             Icon: Boxes,
-            wide: true,
             ...s("claudeCode"),
             render: () => <CcConfig />,
           },
@@ -141,7 +137,6 @@ export function SettingsHub() {
             id: "agents/codex",
             group: "agents" as const,
             Icon: SquareTerminal,
-            wide: true,
             ...s("codex"),
             render: () => <CodexConfig />,
           },
@@ -157,14 +152,12 @@ export function SettingsHub() {
         Icon: x.id === "antigravity" ? Orbit : Puzzle,
         title: x.label,
         description: t("settingsNav.section.tool.description", { tool: x.label }),
-        wide: true,
         render: () => <AiToolConfig key={x.id} toolId={x.id} />,
       })),
     {
       id: "ai-router",
       group: "routing",
       Icon: Router,
-      wide: true,
       ...s("aiRouter"),
       render: () => <AiRouterConfig />,
     },
@@ -172,13 +165,25 @@ export function SettingsHub() {
       id: "pricing",
       group: "routing",
       Icon: Coins,
-      wide: true,
       ...s("pricing"),
       render: () => (
         <div className="space-y-6">
-          <PricingSettings vendor="claude" allowReset id="pricing-claude" />
-          <PricingSettings vendor="openai" id="pricing-openai" />
-          <PricingSettings vendor="google" id="pricing-google" />
+          <PricingSettings
+            vendor="claude"
+            allowReset
+            id="pricing-claude"
+            heading={t("pricing.vendor.claude")}
+          />
+          <PricingSettings
+            vendor="openai"
+            id="pricing-openai"
+            heading={t("pricing.vendor.openai")}
+          />
+          <PricingSettings
+            vendor="google"
+            id="pricing-google"
+            heading={t("pricing.vendor.google")}
+          />
         </div>
       ),
     },
@@ -304,7 +309,7 @@ export function SettingsHub() {
           })}
         </nav>
 
-        <div className={`min-w-0 flex-1 ${active.wide ? "" : "max-w-3xl"}`}>
+        <div className="min-w-0 flex-1">
           <select
             aria-label={t("settingsNav.label")}
             value={active.id}