feat(dashboard): add project_id display for Antigravity accounts

Display GCP project_id for Antigravity (agy) accounts in the Dashboard:

- Add projectId field to AccountInfo interface (account-manager.ts)
- Read project_id from auth files when discovering/registering accounts
- Pass projectId through token-manager when registering new accounts
- Add projectId to OAuthAccount type (api-client.ts)
- Add projectId to AccountRow type (auth-monitor/types.ts)
- Display project_id in account-item.tsx with FolderCode icon
- Show N/A warning with amber tooltip if project_id is missing
  suggesting user remove and re-add account to fetch it

Note: project_id is read-only and respects privacy mode blur.

src/cliproxy/account-manager.ts

@@ -47,6 +47,8 @@ export interface AccountInfo {
   pausedAt?: string;
   /** Account tier: free or paid (Pro/Ultra combined) */
   tier?: AccountTier;
+  /** GCP Project ID (Antigravity only) - read-only, fetched from auth token */
+  projectId?: string;
 }
 
 /** Provider accounts configuration */
@@ -293,7 +295,8 @@ export function registerAccount(
   provider: CLIProxyProvider,
   tokenFile: string,
   email?: string,
-  nickname?: string
+  nickname?: string,
+  projectId?: string
 ): AccountInfo {
   const registry = loadAccountsRegistry();
 
@@ -350,7 +353,7 @@ export function registerAccount(
   const isFirstAccount = Object.keys(providerAccounts.accounts).length === 0;
 
   // Create or update account
-  providerAccounts.accounts[accountId] = {
+  const accountMeta: Omit<AccountInfo, 'id' | 'provider' | 'isDefault'> = {
     email,
     nickname: accountNickname,
     tokenFile,
@@ -358,6 +361,13 @@ export function registerAccount(
     lastUsedAt: new Date().toISOString(),
   };
 
+  // Include projectId for Antigravity accounts
+  if (provider === 'agy' && projectId) {
+    accountMeta.projectId = projectId;
+  }
+
+  providerAccounts.accounts[accountId] = accountMeta;
+
   // Set as default if first account
   if (isFirstAccount) {
     providerAccounts.default = accountId;
@@ -671,13 +681,20 @@ export function discoverExistingAccounts(): void {
       // Register account with auto-generated nickname
       // Use mtime as lastUsedAt (when token was last modified = last auth/refresh)
       const lastModified = stats.mtime || stats.birthtime || new Date();
-      providerAccounts.accounts[accountId] = {
+      const accountMeta: Omit<AccountInfo, 'id' | 'provider' | 'isDefault'> = {
         email,
         nickname: generateNickname(email),
         tokenFile: file,
         createdAt: stats.birthtime?.toISOString() || new Date().toISOString(),
         lastUsedAt: lastModified.toISOString(),
       };
+
+      // Read project_id for Antigravity accounts (read-only field from auth token)
+      if (provider === 'agy' && data.project_id) {
+        accountMeta.projectId = data.project_id;
+      }
+
+      providerAccounts.accounts[accountId] = accountMeta;
     } catch {
       // Skip invalid files
       continue;

src/cliproxy/auth/token-manager.ts

@@ -229,8 +229,15 @@ export function registerAccountFromToken(
     const content = fs.readFileSync(tokenPath, 'utf-8');
     const data = JSON.parse(content);
     const email = data.email || undefined;
+    const projectId = data.project_id || undefined;
 
-    return registerAccount(provider, newestFile, email, nickname || generateNickname(email));
+    return registerAccount(
+      provider,
+      newestFile,
+      email,
+      nickname || generateNickname(email),
+      projectId
+    );
   } catch {
     return null;
   }