nas-samba v1.0.1: health check, hostname, remove demo credentials

- Add health check (curl /api/health) so Traefik can verify container health
- Set container hostname to nas.alexzaw.dev
- Remove hardcoded demo credentials from login page
- Remove admin123 fallback password — require SMB_PASSWORD env var
- Fail fast if no admin password is configured

apps/nas-samba/config.json

@@ -8,7 +8,7 @@
   "dynamic_config": true,
   "no_gui": false,
   "tipi_version": 2,
-  "version": "1.0.0",
+  "version": "1.0.1",
   "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",