CI: stand up Gitea Actions (TST-03) + fix the defects it caught (#123)

Make the authored CI pipeline execute and go green on the co-located runner (portable + java), fix the five real latent defects the first real run surfaced (codegen-check null, stale rust proto, orphan-terminator Linux path, stale java worker codegen, py3.12 event loop), provision pwsh + Gradle for the self-hosted act image, and disable the Windows jobs (act host-mode broken). TST-03 -> Done.

https://claude.ai/code/session_01DMXXvNuPekkkrTEyPNxEkW

src/ZB.MOM.WW.MxGateway.Tests/Gateway/Workers/OrphanWorkerTerminatorTests.cs

@@ -13,7 +13,19 @@ namespace ZB.MOM.WW.MxGateway.Tests.Gateway.Workers;
 /// </summary>
 public sealed class OrphanWorkerTerminatorTests
 {
-    private const string WorkerExecutablePath = @"C:\app\src\ZB.MOM.WW.MxGateway.Worker\bin\x86\Release\ZB.MOM.WW.MxGateway.Worker.exe";
+    // An OS-appropriate, already-normalized absolute path so Path.GetFullPath (used by the
+    // terminator to resolve the configured path) is idempotent and the exact-match compare holds
+    // on every platform. A hard-coded Windows literal (C:\...) is not rooted on Linux, so
+    // Path.GetFullPath there prepends the cwd and the match fails — the terminator is a
+    // Windows-only feature in production, but its matching logic must still be testable on the
+    // Linux CI runner.
+    private static readonly string WorkerExecutablePath = Path.GetFullPath(Path.Combine(
+        Path.GetTempPath(),
+        "MxGatewayOrphanTests",
+        "bin",
+        "x86",
+        "Release",
+        "ZB.MOM.WW.MxGateway.Worker.exe"));
 
     /// <summary>Verifies that orphan worker processes matching the configured executable path are killed.</summary>
     [Fact]
@@ -59,7 +71,10 @@ public sealed class OrphanWorkerTerminatorTests
         // not our worker and must be left alone.
         FakeProcessInspector inspector = new(
         [
-            new RunningProcessInfo(301, @"C:\other\place\ZB.MOM.WW.MxGateway.Worker.exe"),
+            new RunningProcessInfo(301, Path.GetFullPath(Path.Combine(
+                Path.GetTempPath(),
+                "MxGatewayOrphanTests-other",
+                "ZB.MOM.WW.MxGateway.Worker.exe"))),
         ]);
         OrphanWorkerTerminator terminator = CreateTerminator(inspector);