chore(java): pre-merge simplifier pass — verify-conformance harness

Drop unused HashMap/HashSet imports left over from an earlier draft —
the test uses LinkedHashMap (to keep partial-map order stable) and
Set.of() for the verify-code typo-guard. The four contract checks
(sorted-multiset, determinism, typo guard, provider default) are
unchanged.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: dmealing

server/java/render/src/test/java/com/metaobjects/render/VerifyConformanceTest.java

@@ -13,8 +13,6 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Comparator;
-import java.util.HashMap;
-import java.util.HashSet;
 import java.util.LinkedHashMap;
 import java.util.List;
 import java.util.Map;