fix: improve Gmail connect instructions and add troubleshooting

Clarify that Gmail uses App Passwords (not OAuth login popup), emphasize
2-Step Verification prerequisite, and add a collapsible troubleshooting
section for common issues. Also improve the error message when Gmail
auth fails to specifically mention App Password requirements.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

frontend/src/pages/DataSourcesPage.tsx

@@ -369,7 +369,11 @@ function DataSourcesSection() {
       loadConnectors();
       loadSyncStatuses();
     } catch (err: any) {
-      setConnectError(err.message || 'Connection failed');
+      let errorMsg = err.message || 'Connection failed';
+      if (id === 'gmail_imap' && (errorMsg.includes('auth') || errorMsg.includes('credentials') || errorMsg.includes('LOGIN'))) {
+        errorMsg = 'Invalid credentials — make sure you\'re using an App Password (16 characters), not your regular Gmail password.';
+      }
+      setConnectError(errorMsg);
       setConnectStage('');
     } finally {
       setLoading(false);
@@ -562,6 +566,20 @@ function DataSourcesSection() {
                         onSubmit={(req) => handleConnect(c.connector_id, req)}
                       />
                     )}
+                    {meta?.troubleshooting && (
+                      <details className="mt-2">
+                        <summary className="text-[11px] cursor-pointer" style={{ color: 'var(--color-text-tertiary)' }}>
+                          Having trouble?
+                        </summary>
+                        <ul className="mt-1 space-y-1">
+                          {meta.troubleshooting.map((tip: string, i: number) => (
+                            <li key={i} className="text-[11px]" style={{ color: 'var(--color-text-tertiary)' }}>
+                              {tip}
+                            </li>
+                          ))}
+                        </ul>
+                      </details>
+                    )}
                     {/* Connection progress */}
                     {connectingId === c.connector_id && connectStage && (
                       <div style={{ marginTop: 8 }}>

frontend/src/types/connectors.ts

@@ -14,6 +14,7 @@ export interface ConnectorMeta {
   description: string;
   unitLabel?: string;  // "emails", "messages", "meeting notes", "pages", "notes", etc.
   steps?: SetupStep[];
+  troubleshooting?: string[];
   inputFields?: Array<{
     name: string;
     placeholder: string;
@@ -65,16 +66,23 @@ export const SOURCE_CATALOG: ConnectorMeta[] = [
     unitLabel: 'emails',
     steps: [
       {
-        label: 'Go to your Google account security settings and make sure 2-Step Verification is turned ON (required for app passwords)',
+        label: 'Go to your Google Account \u2192 Security \u2192 2-Step Verification. Make sure it\'s turned ON. App Passwords only work if 2-Step Verification is enabled.',
         url: 'https://myaccount.google.com/signinoptions/two-step-verification',
-        urlLabel: 'Open Google Security',
+        urlLabel: 'Open Google Security \u2192',
       },
       {
-        label: 'Go to App Passwords (myaccount.google.com/apppasswords). Select app: "Mail", select device: "Other" and type "OpenJarvis". Click Generate. Google will show a 16-character password — copy it now (you won\'t see it again)',
+        label: 'Go to App Passwords. Select app: "Mail", device: "Other" and type "OpenJarvis". Click Generate. This does NOT open a login popup \u2014 you\'ll get a 16-character password to copy (you won\'t see it again).',
         url: 'https://myaccount.google.com/apppasswords',
-        urlLabel: 'Open App Passwords',
+        urlLabel: 'Open App Passwords \u2192',
       },
-      { label: 'Enter your Gmail address and the 16-character app password below (spaces are fine)' },
+      {
+        label: 'Paste your Gmail address and the 16-character app password below (spaces are fine). Use the app password, NOT your regular Gmail password.',
+      },
+    ],
+    troubleshooting: [
+      "Don't see App Passwords? Make sure 2-Step Verification is enabled first.",
+      "Google Workspace user? Your admin may need to enable App Passwords for your organization.",
+      "Want OAuth instead? Use the Google Drive connector \u2014 it covers Gmail content too.",
     ],
     inputFields: [
       { name: 'email', placeholder: 'you@gmail.com', type: 'text' },