refactor: Move pezkuwi-sdk-ui to separate repo, add postinstall for mobile

- Remove pezkuwi-sdk-ui from pwap (now at /home/mamostehp/pezkuwi-sdk-ui)
- Add scripts/fix-pezkuwi-packages.cjs for @pezkuwi package path fixes
- Add postinstall hook to mobile package.json
- Update metro.config.cjs documentation
- Update backend @pezkuwi/api version to 16.5.11

pezkuwi-sdk-ui is now a standalone repo at:
https://github.com/pezkuwichain/pezkuwi-sdk-ui

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

backend/package.json

@@ -9,7 +9,7 @@
     "dev": "node --watch src/index.js"
   },
   "dependencies": {
-    "@pezkuwi/api": "^16.5.9",
+    "@pezkuwi/api": "^16.5.11",
     "@pezkuwi/util": "^14.0.11",
     "@pezkuwi/util-crypto": "^14.0.11",
     "cors": "^2.8.5",