tools(skills): add encrypted-dns-skill (ednsdiag CLI + agent skill)

.agents/skills/encrypted-dns-skill/internal/edns/test_helpers_test.go

@@ -0,0 +1,7 @@
+package edns
+
+import "encoding/base64"
+
+func decodeGETQuery(value string) ([]byte, error) {
+	return base64.RawURLEncoding.DecodeString(value)
+}