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/source/smb.conf

@@ -9,10 +9,11 @@
    server min protocol = SMB2
    server max protocol = SMB3
 
-[data]
-   path = /nas
-   valid users = alexz
-   browsable = yes
-   writable = yes
+[homes]
+   comment = Home Directory
+   browseable = no
+   read only = no
+   valid users = %S
+   path = /nas/home/%S
    create mask = 0664
    directory mask = 0775