fix: Address code review for NeverSchema validator tests

- Pin the exact NeverSchema failure message with isEqualTo instead of contains
- Assert that pointer round-trips into the ValidationError
- Assert the rejected value is captured, closing the Task 1 review's
  require vs fail regression risk

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

Author: thced

src/test/java/com/retailsvc/http/validate/DefaultValidatorDispatchTest.java

@@ -82,10 +82,13 @@ void neverSchemaRejectsString() {
             t -> {
               var err = ((ValidationException) t).error();
               assertThat(err.keyword()).isEqualTo("false");
-              assertThat(err.message()).contains("rejects all values");
+              assertThat(err.message()).isEqualTo("schema rejects all values");
+              assertThat(err.pointer()).isEqualTo("/v");
+              assertThat(err.rejectedValue()).isEqualTo("anything");
             });
   }
 
+  // Full ValidationError surface is verified by neverSchemaRejectsString; these cover keyword only.
   @Test
   void neverSchemaRejectsInteger() {
     assertThatThrownBy(() -> v.validate(42, new NeverSchema(), "/v"))