refactor: Return unmodifiable view from Request.afterHooks()

Author: thced

src/main/java/com/retailsvc/http/Request.java

@@ -3,6 +3,7 @@
 import java.net.URLDecoder;
 import java.nio.charset.StandardCharsets;
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;
@@ -271,7 +272,7 @@ public void afterResponse(Runnable runnable) {
 
   /** Internal accessor for the after-hook queue; used by RequestPreparationFilter. */
   public List<Runnable> afterHooks() {
-    return afterHooks;
+    return Collections.unmodifiableList(afterHooks);
   }
 
   private static Map<String, String> parseQuery(String query) {

src/test/java/com/retailsvc/http/RequestTest.java

@@ -272,7 +272,12 @@ void withPrincipalsSharesAfterHookQueue() {
     }
 
     assertThat(log).containsExactly("from-original", "from-enriched");
-    assertThat(original.afterHooks()).isSameAs(enriched.afterHooks());
+    // Adding via one Request is visible via the other — the backing list is shared.
+    original.afterResponse(() -> log.add("from-original-again"));
+    List<Runnable> enrichedView = enriched.afterHooks();
+    assertThat(enrichedView).hasSize(3);
+    enrichedView.get(2).run();
+    assertThat(log).containsExactly("from-original", "from-enriched", "from-original-again");
   }
 
   @Test