Refactor kafka to pure Go (franz-go), fix DBC stubs, update Dockerfile

pkg/utils/localtests/localtests.go

@@ -0,0 +1,11 @@
+// Package localtests provides test utilities for local development.
+package localtests
+
+import "os"
+
+// SkipIfNotLocal skips the test if not running locally
+func SkipIfNotLocal(t interface{ Skip(...any) }) {
+	if os.Getenv("LOCAL_TESTS") != "true" {
+		t.Skip("Skipping local-only test")
+	}
+}