fix(campaigns,tests): admin cannot create campaigns, manager can delete unstarted tests, intensify red/blue team colors

- Campaign creation and generate-from-threat-actor now use the strict
  role check — admin no longer gets a free pass into campaign content,
  same principle already applied to test-template creation.
- New manager-only DELETE /tests/{id}: removes a standalone test still
  in draft (not started, not linked to any campaign).
- Replaced the orange/indigo stand-ins used across team badges, tabs,
  action buttons, and timers with true red/blue so Red Team and Blue
  Team read unambiguously at a glance.

backend/app/services/test_crud_service.py

@@ -438,6 +438,28 @@ def get_test_or_raise(db: Session, test_id: uuid.UUID) -> Test:
     return test
 
 
+def delete_test(db: Session, test_id: uuid.UUID) -> None:
+    """Delete a standalone, not-yet-started test from the queue.
+
+    Only a test still in ``draft`` (execution hasn't started) and not
+    linked to any campaign may be deleted this way — a test already being
+    worked on, or one that's part of a campaign's plan, must be handled
+    through the normal workflow/campaign-modification paths instead.
+    Raises EntityNotFoundError, BusinessRuleViolation. Does not commit;
+    caller commits.
+    """
+    test = get_test_or_raise(db, test_id)
+
+    if test.state != TestState.draft:
+        raise BusinessRuleViolation("Only tests that haven't started yet can be deleted")
+
+    in_campaign = db.query(CampaignTest).filter(CampaignTest.test_id == test.id).first()
+    if in_campaign:
+        raise BusinessRuleViolation("Cannot delete a test that belongs to a campaign")
+
+    db.delete(test)
+
+
 # Define function get_test_with_technique
 def get_test_with_technique(db: Session, test_id: uuid.UUID) -> Test:
     """Fetch a test with technique joined. Raises EntityNotFoundError if not found.