feat: migrate email send to V3 action; deprecate api.py legacy endpoints

- Add /v3/action/email/send router (api_v3_actions_email.py) replacing /util/email/send
- Disable util_email router in registry; register new email action router
- Mark /api/request_jwt and /api/temp_token as deprecated (TODO: remove)
- Guide: add §8 Email Send Action, mark Axonius section EXPIRED, renumber §9-§11

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

app/routers/api_v3_actions_email.py

@@ -0,0 +1,78 @@
+"""
+Aether API V3 - Email Action Router
+-------------------------------------
+Handles transactional email sending.
+
+Routes:
+  POST /send — send a transactional email
+
+Replaces: POST /util/email/send (legacy — see util_email.py)
+"""
+
+import logging
+from typing import Optional
+
+from fastapi import APIRouter, Depends, Query, Response
+from pydantic import BaseModel, Field
+
+from app.lib_email import send_email
+from app.lib_general_v3 import AccountContext, get_account_context
+from app.models.response_models import Resp_Body_Base, mk_resp
+
+log = logging.getLogger(__name__)
+
+router = APIRouter()
+
+
+class EmailSendRequest(BaseModel):
+    from_email: str = Field(..., description="Sender email address")
+    from_name: Optional[str] = None
+    to_email: str = Field(..., description="Recipient email address")
+    to_name: Optional[str] = None
+    cc_email: Optional[str] = None
+    cc_name: Optional[str] = None
+    bcc_email: Optional[str] = None
+    bcc_name: Optional[str] = None
+    subject: str = Field(..., description="Email subject line")
+    body_html: str = Field(..., description="HTML email body")
+    body_text: Optional[str] = None
+
+
+@router.post('/send', response_model=Resp_Body_Base)
+async def action_email_send(
+        req: EmailSendRequest,
+        test: bool = Query(False, description="Simulate send without delivering"),
+        account_ctx: AccountContext = Depends(get_account_context),
+        response: Response = Response,
+        ):
+    log.setLevel(logging.INFO)
+
+    success = send_email(
+        from_email=req.from_email,
+        from_name=req.from_name,
+        to_email=req.to_email,
+        to_name=req.to_name,
+        cc_email=req.cc_email or '',
+        cc_name=req.cc_name or '',
+        bcc_email=req.bcc_email or '',
+        bcc_name=req.bcc_name or '',
+        subject=req.subject,
+        body_text=req.body_text,
+        body_html=req.body_html,
+        test=test,
+    )
+
+    if success:
+        status_code = 200
+        status_message = f'Email sent to <{req.to_email}>.'
+    else:
+        status_code = 400
+        status_message = f'Email failed to send to <{req.to_email}>.'
+
+    log.info(status_message)
+    resp_data = {
+        'from_email': req.from_email,
+        'to_email': req.to_email,
+        'subject': req.subject[:40],
+    }
+    return mk_resp(data=resp_data, status_code=status_code, response=response, status_message=status_message)