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/config.json

@@ -8,7 +8,7 @@
   "dynamic_config": true,
   "no_gui": false,
   "tipi_version": 2,
-  "version": "1.0.2",
+  "version": "2.0.0",
   "categories": ["network", "utilities"],
   "description": "All-in-one NAS container with Samba SMB file sharing and CloudNAS web file manager. Browse files via web UI or connect via SMB at \\\\192.168.0.15\\data with username alexz. No database required — uses filesystem + SQLite.",
   "short_desc": "NAS with SMB + web file manager",