Guard demo seed migrations

Backend/Migrations/20260629142749_SeedRealisticDemoScenario.cs

@@ -10,6 +10,13 @@ public partial class SeedRealisticDemoScenario : Migration
     {
         migrationBuilder.Sql(
             """
+            DO $vtsa_seed$
+            BEGIN
+            IF EXISTS (SELECT 1 FROM "Seasons" WHERE "Year" IN (2025, 2026)) THEN
+                RAISE NOTICE 'Existing seasons detected; skipping realistic demo seed.';
+                RETURN;
+            END IF;
+
             INSERT INTO "Seasons" (
                 "Id", "Year", "Name", "IsDemo", "IsCurrent", "IsCommunityOnly", "CurrentPhase",
                 "NominationStartsAt", "NominationEndsAt", "VotingStartsAt", "VotingEndsAt",
@@ -240,6 +247,8 @@ public partial class SeedRealisticDemoScenario : Migration
             SELECT setval(pg_get_serial_sequence('"ShowactApplications"', 'Id'), COALESCE((SELECT MAX("Id") FROM "ShowactApplications"), 1));
             SELECT setval(pg_get_serial_sequence('"Sponsors"', 'Id'), COALESCE((SELECT MAX("Id") FROM "Sponsors"), 1));
             SELECT setval(pg_get_serial_sequence('"RiskFlags"', 'Id'), COALESCE((SELECT MAX("Id") FROM "RiskFlags"), 1));
+            END;
+            $vtsa_seed$;
             """
         );
     }

Backend/Migrations/20260629144001_AdjustDemoSubcategoriesAndArchive.cs

@@ -10,6 +10,18 @@ public partial class AdjustDemoSubcategoriesAndArchive : Migration
     {
         migrationBuilder.Sql(
             """
+            DO $vtsa_adjust$
+            BEGIN
+            IF EXISTS (
+                SELECT 1
+                FROM "Seasons"
+                WHERE "Year" IN (2024, 2025, 2026)
+                  AND "Id" NOT IN (999, 1000, 1001)
+            ) THEN
+                RAISE NOTICE 'Existing non-demo season years detected; skipping demo archive reseed.';
+                RETURN;
+            END IF;
+
             DELETE FROM "RiskFlags" WHERE "SeasonId" IN (999, 1000, 1001);
             DELETE FROM "Seasons" WHERE "Id" IN (999, 1000, 1001) AND "IsDemo" = TRUE;
             DELETE FROM "StreamerIdentities" WHERE "Id" BETWEEN 3001 AND 3020;
@@ -275,6 +287,8 @@ public partial class AdjustDemoSubcategoriesAndArchive : Migration
             SELECT setval(pg_get_serial_sequence('"ShowactApplications"', 'Id'), COALESCE((SELECT MAX("Id") FROM "ShowactApplications"), 1));
             SELECT setval(pg_get_serial_sequence('"Sponsors"', 'Id'), COALESCE((SELECT MAX("Id") FROM "Sponsors"), 1));
             SELECT setval(pg_get_serial_sequence('"RiskFlags"', 'Id'), COALESCE((SELECT MAX("Id") FROM "RiskFlags"), 1));
+            END;
+            $vtsa_adjust$;
             """
         );
     }