chore(db): annotate the contract-phase drops for the migration-safety gate

Author: waleedlatif1

packages/db/migrations/0275_drop_legacy_folder_tables.sql

@@ -226,6 +226,13 @@ ALTER TABLE "workspace_files" VALIDATE CONSTRAINT "workspace_files_folder_id_fol
 -- is an index on the LIVE `workflow` table, so anything globbing `workflow_folder*` would take
 -- out a production index. Their own FKs and indexes go with them; nothing references either
 -- table, so no CASCADE is needed and its absence is the safety check.
+--
+-- The cutover that stopped all reads and writes of these two tables shipped in EARLIER deploys
+-- (#6037 / #6045), not in this PR. Production has since drained — last legacy write 06:27:21Z,
+-- verified >10h earlier — and the full-row comparison described at the top of this file confirms
+-- nothing is stranded. Step 1 rescues any straggler regardless.
+-- migration-safe: reads/writes ceased in an earlier deploy; drained and full-row verified.
 DROP TABLE IF EXISTS "workflow_folder";
 --> statement-breakpoint
+-- migration-safe: same cutover, same drain, same full-row verification as the drop above.
 DROP TABLE IF EXISTS "workspace_file_folders";