feat: click email row opens it in Gmail (noopener/noreferrer)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/pages/FolderView.jsx

@@ -119,7 +119,16 @@ export default function FolderView() {
         <table className="email-list">
           <tbody>
             {emails.map((e) => (
-              <tr key={e.id} className={`email-row${e.isUnread ? ' email-row--unread' : ''}`}>
+              <tr
+                key={e.id}
+                className={`email-row${e.isUnread ? ' email-row--unread' : ''}`}
+                onClick={() => window.open(
+                  `https://mail.google.com/mail/u/0/#all/${e.gmailMessageId}`,
+                  '_blank',
+                  'noopener,noreferrer'
+                )}
+                title="Open in Gmail"
+              >
                 <td className="el-unread">{e.isUnread && <span className="unread-dot" />}</td>
                 <td className="el-sender" title={e.senderAddress}>
                   {e.senderDisplayName || e.senderAddress}

frontend/src/styles.css

@@ -209,7 +209,7 @@ input, select { background: var(--panel-2); border: 1px solid #2c3550; color: va
 .fv-error { color: var(--danger); font-size: 14px; padding: 12px 0; }
 
 .email-list { width: 100%; border-collapse: collapse; font-size: 13px; }
-.email-row { border-bottom: 1px solid #2c3550; cursor: default; }
+.email-row { border-bottom: 1px solid #2c3550; cursor: pointer; }
 .email-row:hover { background: var(--panel); }
 .email-row--unread .el-sender,
 .email-row--unread .el-subj-text { font-weight: 700; color: var(--text); }