fix(vps): drop Windows License toggle from estimator

Windows BYOL is free and doesn't change the price, so the toggle
was UI clutter. The Included With All Plans card already
communicates the BYOL requirement (line updated to read
"Linux included; Windows supported (bring your own license)" for
clarity), and OS template selection at checkout still lets users
pick a Windows image when they're ready to deploy.

- AddOnsPanel.vue: removed the Windows License switch
- EstimatorSection.vue: removed onWindowsChange handler
- stores/estimator.ts: removed windowsLicense state, dropped from
  share/checkout URL params and hydration
- ConfigOptionSeeder.php: dropped the legacy 'Windows License'
  option from the VPS Add-ons group (deletes existing row)
- CheckoutController.php: removed ?windows=1 query-param handling
  from buildPrefilledSelections
- VpsHosting.vue: tightened the BYOL line in the Included card

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

website/resources/ts/Pages/Marketing/VpsHosting.vue

@@ -63,7 +63,7 @@ const includedFeatures: IncludedItem[] = [
   { text: 'ZFS storage snapshots (free)' },
   { text: 'KVM virtualization' },
   { text: 'Full root access' },
-  { text: 'Linux & Windows (BYOL) support' },
+  { text: 'Linux included; Windows supported (bring your own license)' },
   { text: 'VirtFusion control panel' },
   { text: 'Out-of-band console / VNC access' },
   { text: 'Near-instant provisioning' },