Add typed native WEC runtime observations (#424)

* Observe typed native WEC subscription runtime status

* Link typed WEC runtime changelog to PR 424

* Pass a native null source for subscription runtime queries

* Ignore unused count storage for native null WEC variants

* Keep unavailable WEC source inventories unknown and diagnose native XML reads

* Read native WEC subscription XML with bounded explicit Unicode pipes

* Use bounded Unicode subscription reads in runtime observations and cleanup

* Decode native WEC XML BOMs without unsupported Unicode switch

* Describe strict native WEC XML byte decoding

* Reference System.Xml explicitly when compiling under Windows PowerShell

* Regenerate website changelog snapshots with their proper headers

.gitattributes

@@ -24,5 +24,7 @@
 # Fixed public pending-request fixture is pinned by its exact byte hash.
 /tests/fixtures/adcs-pending-probe.csr text eol=lf
 
+# Native WEC XML reader source identity remains identical across checkouts.
+/modules/WecSubscriptionXml.cs text eol=lf
 scripts/AppLockerProbe.ps1 text eol=lf
 tests/AppLockerProbe*.ps1 text eol=lf