feat(lmxproxy): phase 7 — integration tests, deployment to windev, v1 cutover

- Replaced STA dispatch thread with Task.Run pattern for COM interop
- Fixed TypedValue oneof tracking with property-level _setCase field
- Added x-api-key DelegatingHandler for gRPC metadata authentication
- Fixed CheckApiKey RPC to validate request body key (not header)
- Integration tests: 15/17 pass (reads, subscribes, API keys, connections)
- 2 write tests pending (OnWriteComplete callback timing issue)
- v2 service deployed on windev port 50100

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

lmxproxy/tests/ZB.MOM.WW.LmxProxy.Client.IntegrationTests/appsettings.test.json

@@ -1,9 +1,9 @@
 {
   "LmxProxy": {
-    "Host": "10.100.0.48",
-    "Port": 50052,
-    "ReadWriteApiKey": "REPLACE_WITH_ACTUAL_KEY",
-    "ReadOnlyApiKey": "REPLACE_WITH_ACTUAL_KEY",
+    "Host": "localhost",
+    "Port": 50100,
+    "ReadWriteApiKey": "c4559c7c6acc60a997135c1381162e3c30f4572ece78dd933c1a626e6fd933b4",
+    "ReadOnlyApiKey": "a77d090d4adcfeaac1a50379ec5f971ff282c998599fd8ccf410090c9f290150",
     "InvalidApiKey": "invalid-key-that-does-not-exist"
   }
 }