fix check_names false positives from server steam_id collisions

When a server folder's meta.cpp publishedid appears in a local folder
that has a completely different name, the steam_id lookup was returning
a wrong MISMATCH. Added a two-pass classification: any proposed rename
target that is already an exact OK match for another folder is
reclassified as NOT_ON_SERVER (steam_id collision) instead of MISMATCH.

_resolve_status moved to module level and takes ok_disk_names as a
parameter so it can be unit-tested independently.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

test_suite.py

@@ -1064,7 +1064,7 @@ test("all exported symbols are callable or types", _test_exports_are_callable)
 
 group("check_names helpers")
 
-from check_names import _server_name_from_url, _read_local_steam_id, _lookup_server_name
+from check_names import _server_name_from_url, _read_local_steam_id, _lookup_server_name, _resolve_status
 
 
 def _test_server_name_from_url():
@@ -1143,6 +1143,36 @@ test("_lookup_server_name: falls back to name", _test_lookup_server_name_by_name
 test("_lookup_server_name: steam_id beats name fallback", _test_lookup_server_name_steam_id_beats_name)
 test("_lookup_server_name: not found -> None", _test_lookup_server_name_not_found)
 
+# _resolve_status tests (the false-positive filter)
+
+def _test_resolve_status_ok():
+    status, col = _resolve_status("@ace", "@ace", ok_disk_names={"@ace"})
+    assert_eq(status, "OK")
+    assert_eq(col, "@ace")
+
+def _test_resolve_status_mismatch():
+    status, col = _resolve_status("@ACE3", "@ace3", ok_disk_names={"@cba_a3"})
+    assert_eq(status, "MISMATCH")
+    assert_eq(col, "@ace3")
+
+def _test_resolve_status_not_found():
+    status, col = _resolve_status("@Unknown", None, ok_disk_names=set())
+    assert_eq(status, "NOT_ON_SERVER")
+
+def _test_resolve_status_steam_id_collision():
+    # server_name is already correctly held by another folder → false positive
+    ok = {"@Realistic Ragdoll Physics"}
+    status, col = _resolve_status("@NIArms All in One- ACE Compatibility",
+                                  "@Realistic Ragdoll Physics",
+                                  ok_disk_names=ok)
+    assert_eq(status, "NOT_ON_SERVER", "Should be reclassified due to collision")
+    assert "collision" in col
+
+test("_resolve_status: OK match", _test_resolve_status_ok)
+test("_resolve_status: genuine mismatch", _test_resolve_status_mismatch)
+test("_resolve_status: not found", _test_resolve_status_not_found)
+test("_resolve_status: steam_id collision reclassified as NOT_ON_SERVER", _test_resolve_status_steam_id_collision)
+
 
 # ---------------------------------------------------------------------------
 # 10. Integration: parse → compare → reporter (offline)