fix(dashboard): run residual cron profile I/O off the event loop

Two async handlers still called the cron profile-walk helpers directly on
the FastAPI event loop after the 49fa04a23/346e5673d threadpool migration:

- POST /api/cron/fire called _find_cron_job_profile() inline — it walks
  every profile and lists its jobs (file I/O per profile), stalling the
  loop before the 202 is returned.
- POST /api/cron/blueprints/instantiate called _call_cron_for_profile()
  inline for create_job.

Route both through the existing _run_cron_dashboard_io threadpool wrapper
like every other cron dashboard endpoint.

Credit: @riceharvest (#50948) originally identified the sync-I/O-in-async-
handlers bug class for the desktop boot endpoints; 49fa04a23, 346e5673d,
7d0ddbb2f, d5eee133e and 24d5bda1e have since fixed most of that PR's scope
via the managed threadpool + PID cache + alias-map surfaces. This covers
the two cron handlers those merges missed.

hermes_cli/web_server.py

@@ -10481,7 +10481,10 @@ async def cron_fire_webhook(request: Request):
     if not job_id:
         return JSONResponse({"error": "missing job_id"}, status_code=400)
 
-    profile = _find_cron_job_profile(job_id)
+    # _find_cron_job_profile walks every profile and lists its jobs (file
+    # I/O per profile) — run it off the event loop like the other cron
+    # dashboard endpoints.
+    profile = await _run_cron_dashboard_io(_find_cron_job_profile, job_id)
     if not profile:
         # Job is gone (cancelled / completed) — nothing to fire. 200 so NAS
         # does not retry a fire that is intentionally absent.
@@ -10556,7 +10559,11 @@ async def instantiate_blueprint(body: AutomationBlueprintInstantiate, profile: s
         # Blueprint-created jobs deliver to the dashboard's configured target by
         # default; the form's deliver slot overrides via spec["deliver"].
         spec.pop("origin", None)
-        return _call_cron_for_profile(profile, "create_job", **spec)
+        # create_job does per-profile file I/O — keep it off the event loop
+        # like the sibling cron endpoints (partial avoids **spec keys ever
+        # colliding with the wrapper's own parameters).
+        _create = functools.partial(_call_cron_for_profile, profile, "create_job", **spec)
+        return await _run_cron_dashboard_io(_create)
     except HTTPException:
         raise
     except Exception as e: