ci(windows-drivers): provision WDK + cargo-wdk on the runner (rewrite M0)

The windows-amd64 runner has the base Windows SDK + MSVC + LLVM + Rust but NOT
the WDK (probed: km=False, no um/iddcx, no inf2cat/stampinf/devgen) or cargo-wdk,
so the all-Rust UMDF drivers can't build there yet. Adds an idempotent
provisioning script (scripts/ci/provision-windows-wdk.ps1: download wdksetup 26100
-> /q /norestart, cargo install --locked cargo-wdk, then verify km/wdf + iddcx
headers + inf2cat/stampinf + cargo-wdk) and a workflow_dispatch/push workflow that
runs it on the persistent runner (one-time; install persists).

cargo-wdk (not cargo-make) is windows-drivers-rs's current build+package tool
(cargo build -> stampinf/inf2cat/signtool). Driver builds must pin
Version_Number=10.0.26100.0 (the runner also has 10.0.28000.0, which lacks km/crt).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

.gitea/workflows/windows-drivers-provision.yml

@@ -0,0 +1,27 @@
+# One-shot provisioning of the WDK + cargo-wdk onto the persistent self-hosted windows-amd64 runner, so
+# the all-Rust UMDF drivers can build there (docs/windows-host-rewrite.md, M0). The runner has the base
+# Windows SDK + MSVC + LLVM + Rust but NOT the WDK (no km/wdf/iddcx headers) or cargo-wdk.
+#
+# Dispatch manually (workflow_dispatch). Idempotent: re-running is a near no-op once provisioned. The
+# install persists on the runner (real box, not an ephemeral container), so this runs once, not per build.
+name: windows-drivers-provision
+
+on:
+  workflow_dispatch:
+  push:
+    branches: [main]
+    paths:
+      - 'scripts/ci/provision-windows-wdk.ps1'
+      - '.gitea/workflows/windows-drivers-provision.yml'
+
+jobs:
+  provision:
+    runs-on: windows-amd64
+    timeout-minutes: 60
+    defaults:
+      run:
+        shell: pwsh
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install WDK + cargo-wdk on the runner
+        run: ./scripts/ci/provision-windows-wdk.ps1