refactor(automations): park manual trigger pending Run-now redesign

Manual-as-a-standalone-trigger conflates "user clicks Run now" with the
trigger model and forces ad-hoc input plumbing on the caller. Remove the
unreachable surface so the tree reflects reality (schedule is the only
v1 trigger).

- Unregister `manual`: drop import from triggers/__init__.py
- Delete `app/automations/triggers/manual/`
- Drop `RunService.dispatch_manual` (RunService is now read-only)
- Drop `POST /automations/{id}/run` and `RunDispatched` schema
- Keep `TriggerType.MANUAL` Python + PG enum value (reserved, documented)
  to avoid an Alembic round-trip when Run-now is redesigned

surfsense_backend/app/automations/api/run.py

@@ -1,42 +1,15 @@
-"""HTTP routes for automation runs (dispatch + history)."""
+"""HTTP routes for automation run history."""
 
 from __future__ import annotations
 
-from typing import Any
+from fastapi import APIRouter, Depends, Query
 
-from fastapi import APIRouter, Body, Depends, Query, status
-
-from app.automations.schemas.api import (
-    RunDetail,
-    RunDispatched,
-    RunList,
-    RunSummary,
-)
+from app.automations.schemas.api import RunDetail, RunList, RunSummary
 from app.automations.services import RunService, get_run_service
 
 router = APIRouter()
 
 
-@router.post(
-    "/automations/{automation_id}/run",
-    response_model=RunDispatched,
-    status_code=status.HTTP_202_ACCEPTED,
-)
-async def run_automation_now(
-    automation_id: int,
-    inputs: dict[str, Any] | None = Body(default=None),
-    service: RunService = Depends(get_run_service),
-) -> RunDispatched:
-    """Fire a manual run.
-
-    ``inputs`` is the runtime payload supplied by the caller; it is merged with
-    the manual trigger's ``static_inputs`` (static wins) and validated against
-    the automation's input schema.
-    """
-    run = await service.dispatch_manual(automation_id=automation_id, runtime_inputs=inputs)
-    return RunDispatched(run_id=run.id, status=run.status)
-
-
 @router.get(
     "/automations/{automation_id}/runs",
     response_model=RunList,