OUT-4029 | Drop Tasks.label column and Labels table

Removes the label field from the Task Prisma model, deletes the Label model,
and adds the destructive migration (ALTER TABLE Tasks DROP COLUMN label; DROP
TABLE Labels). Runs via prisma migrate deploy in scripts/build.sh at deploy.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: SandipBajracharya

prisma/migrations/20260825000000_drop_task_label_and_labels_table/migration.sql

@@ -0,0 +1,2 @@
+ALTER TABLE "Tasks" DROP COLUMN "label";
+DROP TABLE "Labels";

prisma/schema/label.prisma

@@ -11,7 +11,6 @@ enum Source {
 
 model Task {
   id              String        @id @default(dbgenerated("gen_random_uuid()")) @db.Uuid
-  label           String
   workspaceId     String        @db.VarChar(32)
   assigneeId      String?       @db.Uuid
   internalUserId  String?       @db.Uuid