fix(campaigns): start_date modal + hide future-campaign tests from queue

Backend: activate endpoint returns 409 with structured warning when
start_date is in the future; accepts force=true to bypass.
test_crud_service: always excludes tests from draft campaigns with future
start_date so they do not appear in the team queue prematurely.

Frontend: catches 409 on activate and shows amber confirmation modal
with Keep scheduled / Activate now anyway options.

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

backend/app/services/test_crud_service.py

@@ -19,7 +19,7 @@ from app.models.enums import TestState
 from app.models.technique import Technique
 from app.models.test import Test
 from app.models.test_template import TestTemplate
-from app.models.campaign import CampaignTest
+from app.models.campaign import Campaign, CampaignTest
 from app.models.audit import AuditLog
 from app.utils import escape_like
 
@@ -36,7 +36,12 @@ def list_tests(
     offset: int = 0,
     limit: int = 50,
 ) -> list[Test]:
-    """Return a paginated list of tests with optional filters."""
+    """Return a paginated list of tests with optional filters.
+
+    Tests that belong to a campaign still in 'draft' status AND with a
+    start_date in the future are always excluded — they should not appear
+    in the team's queue until the campaign is activated on its start date.
+    """
     query = db.query(Test).options(joinedload(Test.technique))
 
     if state:
@@ -61,6 +66,22 @@ def list_tests(
         linked = db.query(CampaignTest.test_id).distinct().subquery()
         query = query.filter(~Test.id.in_(linked))
 
+    # Always hide tests from scheduled campaigns that haven't started yet.
+    # A "scheduled-but-not-yet-active" campaign = draft status + start_date in future.
+    now = datetime.utcnow()
+    future_draft_tests = (
+        db.query(CampaignTest.test_id)
+        .join(Campaign, Campaign.id == CampaignTest.campaign_id)
+        .filter(
+            Campaign.status == "draft",
+            Campaign.start_date.isnot(None),
+            Campaign.start_date > now,
+        )
+        .distinct()
+        .subquery()
+    )
+    query = query.filter(~Test.id.in_(future_draft_tests))
+
     return query.order_by(Test.created_at.desc()).offset(offset).limit(limit).all()