Build temetro app: dark theme, clinical sidebar, AI chat, settings page

- Linear-inspired dark theme (app/globals.css), forced dark in layout
- Clinical sidebar (components/sidebar-02) with temetro brand
- AI chat UI (components/chat): Cursor-style input, UI-only mock replies
- Settings page (components/settings): Polar-style tabs/sections, UI only
- Route-group app shell: app/(app)/{layout,page,settings}
- shadcn (Base UI) + ai-elements component libraries
- CLAUDE.md: architecture notes + per-folder commit policy

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

frontend/app/(app)/layout.tsx

@@ -0,0 +1,17 @@
+import { SidebarProvider } from "@/components/ui/sidebar";
+import { DashboardSidebar } from "@/components/sidebar-02/app-sidebar";
+
+export default function AppLayout({
+  children,
+}: {
+  children: React.ReactNode;
+}) {
+  return (
+    <SidebarProvider>
+      <div className="relative flex h-dvh w-full">
+        <DashboardSidebar />
+        {children}
+      </div>
+    </SidebarProvider>
+  );
+}

frontend/app/(app)/page.tsx

@@ -0,0 +1,10 @@
+import { SidebarInset } from "@/components/ui/sidebar";
+import { ChatPanel } from "@/components/chat/chat-panel";
+
+export default function Home() {
+  return (
+    <SidebarInset className="flex flex-1 flex-col overflow-hidden">
+      <ChatPanel />
+    </SidebarInset>
+  );
+}

frontend/app/(app)/settings/page.tsx

@@ -0,0 +1,10 @@
+import { SidebarInset } from "@/components/ui/sidebar";
+import { SettingsView } from "@/components/settings/settings-view";
+
+export default function SettingsPage() {
+  return (
+    <SidebarInset className="flex flex-1 flex-col overflow-y-auto">
+      <SettingsView />
+    </SidebarInset>
+  );
+}