Add scheduled maintenance, PC list export, and subnet scanner scripts

- Schedule-Maintenance.ps1: DPAPI credential storage + Task Scheduler integration
- Export-PCList.ps1: Pull PC lists from ShopDB API with type/BU filtering
- Find-ShopfloorPCs.ps1: Parallel subnet scanner with WinRM and DNS checks
- INSTRUCTIONS.txt: Schedule-Maintenance.ps1 documentation

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

remote-execution/INSTRUCTIONS.txt

@@ -0,0 +1,100 @@
+============================================================
+  Schedule-Maintenance.ps1 - Documentation
+============================================================
+
+  Wrapper script that stores credentials securely and
+  runs Invoke-RemoteMaintenance.ps1 unattended or on a
+  schedule via Windows Task Scheduler.
+
+
+============================================================
+REQUIREMENTS
+============================================================
+
+  - PowerShell 5.1+
+  - Run as Administrator (required for scheduling only)
+  - Invoke-RemoteMaintenance.ps1 in the same folder
+  - A PC list text file (one hostname per line)
+
+
+============================================================
+PARAMETERS
+============================================================
+
+  -SaveCredential       Save credentials for unattended use
+  -Username             Domain\username (use with -SaveCredential)
+  -Password             Password (use with -SaveCredential)
+  -Task                 Maintenance task name (e.g. Reboot)
+  -ComputerListFile     Path to text file with PC hostnames
+  -CreateScheduledTask  Register a Windows Scheduled Task
+  -TaskFrequency        Daily, Weekly, or Once (default: Weekly)
+  -TaskDay              Day of week (default: Sunday)
+  -TaskTime             Time in HH:mm format (default: 03:00)
+  -TaskDate             Specific date for Once (e.g. 2026-02-22)
+
+
+============================================================
+USAGE
+============================================================
+
+1. SAVE CREDENTIALS (one time, does not require admin)
+
+   .\Schedule-Maintenance.ps1 -SaveCredential -Username "DS\570005354" -Password "MyP@ssw0rd"
+
+   - Encrypted with Windows DPAPI
+   - Only your user account on this machine can decrypt
+   - Re-run if your password changes
+
+
+2. RUN IMMEDIATELY (does not require admin)
+
+   .\Schedule-Maintenance.ps1 -ComputerListFile ".\shopfloor-pcs.txt" -Task Reboot
+
+
+3. SCHEDULE A ONE-TIME TASK (requires admin)
+
+   # Reboot one PC today at 3:00 PM
+   .\Schedule-Maintenance.ps1 -CreateScheduledTask -ComputerListFile ".\test-reboot.txt" -Task Reboot -TaskFrequency Once -TaskTime "15:00" -TaskDate "2026-02-19"
+
+   # Reboot all PCs Sunday Feb 22 at 12:01 AM
+   .\Schedule-Maintenance.ps1 -CreateScheduledTask -ComputerListFile ".\shopfloor-pcs.txt" -Task Reboot -TaskFrequency Once -TaskTime "00:01" -TaskDate "2026-02-22"
+
+
+4. SCHEDULE A RECURRING TASK (requires admin)
+
+   # Every Sunday at 12:01 AM
+   .\Schedule-Maintenance.ps1 -CreateScheduledTask -ComputerListFile ".\shopfloor-pcs.txt" -Task Reboot -TaskFrequency Weekly -TaskDay Sunday -TaskTime "00:01"
+
+   # Every day at 2:00 AM
+   .\Schedule-Maintenance.ps1 -CreateScheduledTask -ComputerListFile ".\shopfloor-pcs.txt" -Task DiskCleanup -TaskFrequency Daily -TaskTime "02:00"
+
+
+5. MANAGE SCHEDULED TASKS
+
+   Get-ScheduledTask | Where-Object { $_.TaskName -like "ShopfloorMaintenance*" }
+   Start-ScheduledTask -TaskName "ShopfloorMaintenance-Reboot"
+   Unregister-ScheduledTask -TaskName "ShopfloorMaintenance-Reboot"
+
+
+============================================================
+LOGS
+============================================================
+
+  .\logs\maintenance-YYYY-MM-DD_HHMMSS-TaskName.log
+
+
+============================================================
+TROUBLESHOOTING
+============================================================
+
+  "No saved credentials found"
+    -> Run -SaveCredential with -Username and -Password
+
+  "Access is denied" when scheduling
+    -> Right-click PowerShell -> Run as Administrator
+
+  "No credentials provided. Exiting."
+    -> GUI prompt failed. Use -Username and -Password flags
+
+  Password changed
+    -> Re-run -SaveCredential with new password