fix: keep platform hashes cores disagree on

When two cores declare different values for one file, the truth keeps the first and marks the entry hash_conflict. Its hashes pair an entry and never replace the platform's: armsx2's GameIndex.yaml no longer overwrites System.dat's line for LRPS2.

scripts/exporter/baseline.py

@@ -45,8 +45,17 @@ def checked_hashes(entry: dict | None) -> dict | None:
     MT32_CONTROL.ROM against nine sha1, and the one md5 beside them
     replaced System.dat's, another accepted revision. Such a value still
     pairs a renamed file, it never corrects or fills one.
+
+    `hash_conflict` marks an entry whose cores declare different values: the
+    truth kept the first core's, so its hashes describe one revision among
+    those the cores accept. armsx2 and yaps2 disagree on GameIndex.yaml, and
+    armsx2's revision replaced System.dat's line for LRPS2.
     """
-    if not entry or entry.get("validation") is None:
+    if not entry:
+        return entry
+    if entry.get("hash_conflict"):
+        return {k: v for k, v in entry.items() if k not in HASH_FIELDS}
+    if entry.get("validation") is None:
         return entry
     raw = entry["validation"]
     if isinstance(raw, dict):

scripts/truth.py

@@ -316,6 +316,9 @@ def _merge_hashes(
                 existing[h] = [*o_list, *added]
             continue
         if not {str(v).lower() for v in t_list} & {str(v).lower() for v in o_list}:
+            # The value kept is one revision among those the cores accept:
+            # it pairs an entry, it never overrules one (checked_hashes).
+            existing["hash_conflict"] = sorted({*existing.get("hash_conflict", ()), h})
             # Once per process: a run over every platform met the same pair
             # once per platform and opened its output on six copies.
             key = (file_entry["name"], h, str(ours), str(theirs), emu_name)