refactor: reorganize CSS and Tool Workshop page

- Extract styles.css into styles/ directory (tokens, global, utilities, syntax-highlight, pages)
- Extract ToolWorkshopPage into components:
  - ToolTypeListSidebar, ToolTypeEditorPanel, ToolWorkshopMobileView
  - use-tool-workshop hook for state management
- Slim ToolWorkshopPage from 1,269 to 110 lines

Quality gates: tsc --noEmit passes, npm run build passes

apps/web/src/main.tsx

@@ -5,16 +5,25 @@ import { BrowserRouter } from "react-router-dom";
 import { AppRouter } from "./router";
 import { AuthProvider } from "./state/auth";
 import { SessionsProvider } from "./state/sessions";
-import "./styles.css";
+import "./styles/tokens.css";
+import "./styles/global.css";
+import "./styles/utilities.css";
+import "./styles/syntax-highlight.css";
+import "./styles/pages/git-history.css";
+import "./styles/pages/repo-workspace.css";
+import "./styles/pages/projects.css";
+import "./styles/pages/sessions.css";
+import "./styles/pages/ssh-keys.css";
+import "./styles/pages/workspace-detail.css";
 
 ReactDOM.createRoot(document.getElementById("root")!).render(
-  <React.StrictMode>
-    <BrowserRouter>
-      <AuthProvider>
-        <SessionsProvider>
-          <AppRouter />
-        </SessionsProvider>
-      </AuthProvider>
-    </BrowserRouter>
-  </React.StrictMode>
+	<React.StrictMode>
+		<BrowserRouter>
+			<AuthProvider>
+				<SessionsProvider>
+					<AppRouter />
+				</SessionsProvider>
+			</AuthProvider>
+		</BrowserRouter>
+	</React.StrictMode>,
 );