docs(folders): record the 0272 + 0274 dry-run results on the migration

Read-only dry-run against production materialised the complete post-0272 `folder` table from
both source tables and checked every constraint it declares: 34,991 rows, 0 NULL names, 0 PK
collisions between the two source tables, 0 unique-index violations, 0 resource-type or
workspace trigger violations, and 0 parent/user/workspace FK violations. 0272 renames 47
workflow folders and 0 file folders — the latter is what lets pass 2 write raw names.

Author: waleedlatif1

packages/db/migrations/0274_file_folder_cutover_reconcile.sql

@@ -24,10 +24,17 @@
 -- replay, so the post-drain pass is an operational step, not an automatic one.
 --
 -- On an environment where 0272 has not yet run — production at time of writing — 0272 and this
--- file apply back to back and this is a no-op reconcile over the rows 0272 just wrote. Verified
--- against production: 1,493 legacy file folders, 0 active name duplicates, 0 orphaned parents,
--- 0 cross-workspace parents, and 0 id collisions with `workflow_folder`, so the insert path
--- cannot trip the unique index, the FKs, or the resource-type trigger.
+-- file apply back to back and this is a no-op reconcile over the rows 0272 just wrote.
+--
+-- Dry-run against production (read-only), materialising the full post-0272 `folder` table from
+-- both source tables and checking every constraint the table declares: 34,991 rows, and 0 of
+-- each of — NULL names, NULL required columns, primary-key collisions between the two source
+-- tables, `folder_workspace_resource_parent_name_active_unique` violations, resource-type or
+-- workspace violations of `folder_parent_resource_type_match`, and parent/user/workspace FK
+-- violations. Longest generated name 55 chars. 0272's dedup renames 47 workflow folders and 0
+-- file folders (the legacy table's own active-unique index guarantees the latter, which is why
+-- pass 2 below can write raw names). All 5,475 foldered files and 4,593 foldered workflows keep
+-- a resolvable folder id.
 
 -- Wrapped in a DO block so the two passes are ONE statement and therefore atomic on their own.
 -- 0272 ends with an embedded COMMIT (its trailing CONCURRENTLY index builds cannot run inside a