feat(dynamic): enhance corpus sync script with improved payload parsing, registry checks, and expanded validation logic

tests/dynamic_fixtures/java/fileio_adversarial.java

@@ -1,13 +1,16 @@
 // File I/O — adversarial collision fixture.
-// Prints "root:" unconditionally without reading any file
-// and without emitting __NYX_SINK_HIT__.
+// Prints the path-traversal canary marker unconditionally without reading any
+// file and without emitting __NYX_SINK_HIT__, so the oracle observes a marker
+// hit with no sink-reachability.
 // Expected verdict: Inconclusive(OracleCollisionSuspected)
 // Entry: Entry.readFile(String)  Cap: FILE_IO
 
 public class Entry {
     public static void readFile(String userPath) {
-        // Coincidental oracle match — not a file read sink.
-        System.out.println("root: present");
+        // Coincidental oracle match — emits the marker string but is not a
+        // file-read sink and never reaches the planted canary.  Must match the
+        // CANARY_MARKER in src/dynamic/corpus/path_trav/java.rs.
+        System.out.println("NYX_PATHTRAVERSAL_R34D_a7f3c1d8 present");
         int x = userPath.length();
     }
 }