feat(topdata): anchor autogen lock identity on model path with cutover remap

Lock identity for accessory VFX rows is now the model source path
(dataset:group/subgroup/file.mdl) rather than the config-derived
presentation key. Config-only edits (key_format, delimiter, case,
strip_prefixes) no longer reshuffle row IDs.

Adds: accessoryVisualeffectLockKey, hasKey helper, stale pruning loop
(managed keys with no live entry are freed), and one-time cutover remap
(old config-derived key in historical lock → new model-path key, with
the old key pruned). autogenConsumerManagedLockKeyMatcher is now
config-independent (dataset prefix + first path segment ∈ policy groups).

Updates autogen_manifest_file_test.go and topdata_test.go lock-key
assertions to match the new model-path scheme.

internal/topdata/autogen_manifest_file_test.go

@@ -57,7 +57,7 @@ func TestApplyAutogenConsumersReadsManifestFile(t *testing.T) {
 	if row["key"] != "visualeffects:head_accessories/hat/bandana" || row["Imp_HeadCon_Node"] != "hfx_bandana" {
 		t.Fatalf("unexpected generated row: %#v", row)
 	}
-	if _, ok := got[0].LockData["visualeffects:head_accessories/hat/bandana"]; !ok {
+	if _, ok := got[0].LockData["visualeffects:head_accessories/hat/hfx_bandana.mdl"]; !ok {
 		t.Fatalf("expected lock id for generated accessory, got %#v", got[0].LockData)
 	}
 	// Authored key untouched.