nas-samba v2.0.0: per-user home directories, Samba accounts, remove quotas

- Each user gets a Linux + Samba account and home dir at /nas/home/<username>/
- Web UI file browsing scoped to per-user directories
- Creating/deleting users from web UI also manages system + Samba accounts
- Replaced hardcoded [data] SMB share with [homes] (per-user automatic shares)
- Removed hardcoded alexz user from entrypoint — server.js handles all user management
- Removed storage quotas from backend and frontend
- Existing users get home directories auto-created on startup (migration)

apps/nas-samba/docker-compose.json

@@ -4,7 +4,7 @@
   "services": [
     {
       "name": "nas-samba",
-      "image": "git.alexzaw.dev/alexz/nas-samba:1.0.2",
+      "image": "git.alexzaw.dev/alexz/nas-samba:2.0.0",
       "isMain": true,
       "internalPort": 8080,
       "hostname": "nas.alexzaw.dev",