refactor(ekonomi): consolidate Pasar Desa into UMKM module

- Remove "Pasar Desa" as a separate entity; products are now strictly linked to UMKM.
- Delete redundant Pasar Desa API endpoints and state management.
- Update Admin UI: remove "Pasar Desa" menu and unified product management under UMKM.
- Update Public UI: replace "Pasar Desa" with "UMKM" in navbar and unified hub at /darmasaba/ekonomi/umkm.
- Implement mandatory umkmId in PasarDesa model and update seeders accordingly.
- Fix UI bugs, missing imports, and invalid API filters for mandatory umkmId.
- Increment version to 0.1.18.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "desa-darmasaba",
-  "version": "0.1.17",
+  "version": "0.1.18",
   "private": true,
   "scripts": {
     "dev": "next dev",