feat(folders): add resource pinning and generalize the folders contract (#6014)

- Adds per-user pinning for workflows, files, knowledge bases, and tables: new `pinned_item` table, `/api/pinned-items` routes, React Query hooks, and a shared `PinButton` wired into Tables, Knowledge, and Files with pinned-first ordering
- Adds the generic `folder` table with an idempotent, replay-safe, collision-aware backfill from `workflow_folder` and `workspace_file_folders`; no cutover yet, folder reads still go through a documented legacy adapter
- Moves `folderSchema` to the generic vocabulary (`resourceType`, `deletedAt`) and drops the unused `color`/`isExpanded`

scripts/check-api-validation-contracts.ts

@@ -9,8 +9,8 @@ const QUERY_HOOKS_DIR = path.join(ROOT, 'apps/sim/hooks/queries')
 const SELECTOR_HOOKS_DIR = path.join(ROOT, 'apps/sim/hooks/selectors')
 
 const BASELINE = {
-  totalRoutes: 979,
-  zodRoutes: 979,
+  totalRoutes: 981,
+  zodRoutes: 981,
   nonZodRoutes: 0,
 } as const