fix(campaign): align adaptive handbook with shipped UI

src/govoplan_campaign/backend/sending/jobs.py

@@ -544,10 +544,11 @@ def send_campaign_now(
     use_rate_limit: bool = True,
     enqueue_imap_task: bool = False,
 ) -> SendCampaignNowResult:
-    """Queue and send a small campaign synchronously.
+    """Queue and send all eligible jobs for one campaign synchronously.
 
-    This is intended for WebUI test/small-campaign flows. Large campaigns can
-    still use queue_campaign_jobs with Celery workers.
+    The service currently has no server-side job-count bound. Callers must use
+    the worker queue for ordinary batches and reserve this path for deliberately
+    small interactive runs.
     """
 
     campaign = _get_campaign_for_tenant(session, campaign_id=campaign_id, tenant_id=tenant_id)