Generalize USMT Dash and add a containerized demo mode

Remove all environment-specific data and make the dashboard adoptable
anywhere, then add a demo that runs the real PowerShell services.

- Strip cached device data, internal knowledge-base articles and
  screenshots, server/site names and the old project notes; replace the
  knowledge base with generic sample articles and diagrams
- Move every environment value into Config/usmt-dash.psd1
- Route all infrastructure access in the worker and Get-Software.ps1
  through a provider (Providers/SCCM.ps1), with a config-driven asset
  inventory view instead of a hard-coded custom class
- Add Providers/Demo.ps1: a deterministic simulated fleet whose
  migrations progress in real time, and Demo/New-DemoData.ps1 to seed it
- Server: -Demo makes the API read-only; add get-config and get-logs;
  serve static files only from web/, Documentation/ and an allowlist of
  Data/ files with a path-traversal guard; gzip large responses
- Mirror both services' console output to Data/Logs via a Write-Host
  proxy, and add a terminal panel to the dashboard that streams it
- Demo sandbox (web/demo/demo.js): visitor changes to tags, articles and
  images are kept in the visitor's browser and echoed in the terminals;
  nothing a visitor does reaches the server
- Vendor marked, highlight.js and html2pdf.js instead of loading CDNs
- Dockerfile and compose file for hosting the demo (Coolify-ready)

Documentation/QuickBooks.md

@@ -0,0 +1,23 @@
+[[Blue:Licensed]] [[Red:Finance Approval]]
+
+# QuickBooks
+
+QuickBooks Desktop is installed for Accounting and Finance users only. Each install needs a **license and product number** from the Finance team. Never reuse one from another device without approval.
+
+The software scan shows three entries that USMT Dash groups as one *QuickBooks* suite:
+- QuickBooks Desktop Pro
+- QuickBooks Database Server Manager
+- Intuit Data Protect
+
+## Install
+1. Get the license and product number from the Finance team's request ticket.
+2. Run the installer: [[Copy:\\fileserver\software\QuickBooks\Setup_QuickBooks.exe]]
+3. Choose **Custom and Network Options** > *I'll be using QuickBooks on this computer*.
+4. Launch, register, and apply all updates (**Help > Update QuickBooks Desktop**).
+
+## Company Files
+- Company files (`.QBW`) live on the finance share, **not** on the local device: [[Copy:\\fileserver\finance\QuickBooks]]
+- If the user had a local company file, move it to the share. Don't open it from a USB drive.
+
+## Multi-user Mode
+The file server runs **Database Server Manager**. Workstations don't need it unless the user hosts files locally.