feat: refactor conversations page into a workbench layout and implement workspace switching

- Migrate ConversationsPage to use ConversationWorkbench component.
- Create WorkbenchLayout to handle authentication and layout for workbench.
- Add WorkbenchPage to render ConversationWorkbench.
- Implement WorkspaceSwitcher for switching between dashboard and workbench.
- Update AuthProvider to manage authentication for both dashboard and workbench routes.
- Enhance WorkbenchHeader with user menu and workspace switcher.
- Add tests for workspace switcher and auth provider functionality.
- Update translations for workspace labels in English and Chinese.
- Exclude e2e tests from TypeScript compilation.

web/components/auth-provider.test.mjs

@@ -0,0 +1,15 @@
+import assert from "node:assert/strict";
+import { readFile } from "node:fs/promises";
+import test from "node:test";
+
+const source = await readFile(new URL("./auth-provider.tsx", import.meta.url), "utf8");
+
+test("refreshProfile preserves the stored token when the profile payload omits it", () => {
+  assert.match(source, /accessToken:\s*profile\.accessToken\s*\|\|\s*stored\.accessToken/);
+  assert.match(source, /expiresAt:\s*profile\.expiresAt\s*\|\|\s*stored\.expiresAt/);
+});
+
+test("refreshProfile only clears session for explicit auth error codes", () => {
+  assert.match(source, /errorCode\s*===\s*3000\s*\|\|\s*errorCode\s*===\s*3002/);
+  assert.doesNotMatch(source, /catch\s*\([^)]*\)\s*\{\s*clearSession\(\)/);
+});