kms-website: auto-fetch + auto-install GVLKs (no manual key lookup)

Scripts now detect the running edition and fetch the matching GVLK from a
published key list instead of requiring the user to copy one from the table.

- data/products.yaml: add editionid to every Windows/Server entry, plus build
  numbers where an EditionID spans releases (LTSC, Server). Azure Edition left
  unmapped on purpose (collides with Datacenter; KMS may fail there anyway).
- /keys.json: Hugo KEYS output format renders products.yaml as JSON
  (single source of truth). layouts/index.keys.json.
- setup-kms.ps1: when no VL key is installed, read registry EditionID
  (+build/ProductType for server) -> fetch /keys.json -> slmgr /ipk the match
  -> activate. Only acts when not already licensed (never clobbers retail).
- kms-bootstrap.ps1: same for Windows; for Office/Project/Visio, read
  Click-to-Run ProductReleaseIds -> ospp /inpkey the matching GVLK -> /act.
- $env:KMS_KEYS_URL overrides the key-list URL.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

layouts/index.keys.json

@@ -0,0 +1,2 @@
+{{- /* Machine-readable GVLK list for the activation scripts. Served at /keys.json. */ -}}
+{{- dict "windows" .Site.Data.products.windows "windows_server" .Site.Data.products.windows_server "office" .Site.Data.products.office | jsonify (dict "indent" "  ") -}}