OPS-1: startup scripts, autostart task, backup task, ops README, production config

- appsettings.Production.json: Photos:RootPath -> C:\gerbil-data\photos so
  photo files land on a stable host path when ASPNETCORE_ENVIRONMENT=Production
- Start-GerbilManager.ps1: creates data dirs, sets Production env, launches
  AppHost minimised; saves PID for Stop script
- Stop-GerbilManager.ps1: kills AppHost + Vite node processes by PID / port
- Register-AutoStart.ps1: Windows Scheduled Task on user logon (RunLevel Highest)
- Register-BackupTask.ps1: daily 03:00 Scheduled Task for Backup script
- deploy/README.md: Julian ops guide — start/stop commands, phone URL, DHCP
  reservation, firewall rule (Public-profile Wi-Fi), backup/restore procedures,
  prerequisites checklist, troubleshooting table (German)

Co-Authored-By: Claude Sonnet 4.6 (1M context) <noreply@anthropic.com>

GerbilManagerWebAPI/appsettings.Production.json

@@ -0,0 +1,12 @@
+{
+  "Logging": {
+    "LogLevel": {
+      "Default": "Warning",
+      "Microsoft.AspNetCore": "Warning",
+      "Microsoft.EntityFrameworkCore": "Warning"
+    }
+  },
+  "Photos": {
+    "RootPath": "C:\\gerbil-data\\photos"
+  }
+}