feat: add email_send orchestrator tool

Wraps the existing email_utils.send_email helper as an admin-only tool.
Accepts to, subject, body (plain text); newlines converted to <br> for HTML part.
Registered in _CALLABLES, _ALL_DECLARATIONS, and TOOL_ROLES (admin).

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

cortex/tools/notify.py

@@ -2,9 +2,10 @@
 Notification tools — proactively send messages to user channels.
 
 nc_talk_send routes through notification.py → channels.json.
-Requires notification_channel and notification_room set in the user's channels.json.
+email_send uses the server SMTP config from .env (smtp_server, smtp_from_*).
 """
 
+import asyncio
 import logging
 
 from persona import get_user
@@ -12,6 +13,21 @@ from persona import get_user
 logger = logging.getLogger(__name__)
 
 
+async def email_send(to: str, subject: str, body: str) -> str:
+    """Send an email via the server's configured SMTP account."""
+    from email_utils import send_email
+    ok = await asyncio.to_thread(
+        send_email,
+        to_email=to,
+        subject=subject,
+        body_text=body,
+        body_html=body.replace("\n", "<br>"),
+    )
+    if ok:
+        return f"Email sent to {to}."
+    return "Failed to send email — check SMTP configuration in .env."
+
+
 async def nc_talk_send(message: str) -> str:
     """Send a message to the user via their configured notification channel.