test: v1 Copilot — noise reduction validation

.github/sonar-fix-config.yml

@@ -1,4 +1,4 @@
 # Per-repo override: route to Codex instead of the central default's Claude.
 # Everything else (severities, rules allow/deny, etc.) inherits from
 # config/default.yml in the central sonar-fix repo at run time.
-agent: codex
+agent: copilot

src/main/java/clipper2/SonarFixProbeV1Copilot3.java

@@ -0,0 +1,7 @@
+package clipper2;
+
+public class SonarFixProbeV1Copilot3 {
+    public void run() {
+        // Intentionally empty — probe class used only for SonarQube fix-workflow validation
+    }
+}