TGK: harden store adapters and cleanup gaps

Enforce strict type filter matching for NULL lists
FS store skips missing manifest refs to align with error model
Drop empty tgk1_edge stack stub

src/adapters/tgk_store_fs/tgk_store_fs.c

@@ -253,7 +253,7 @@ bool amduat_tgk_store_fs_init(amduat_tgk_store_fs_t *fs,
 
     err = amduat_asl_store_get(asl_store, refs[i], &artifact);
     if (err != AMDUAT_ASL_STORE_OK) {
-      goto cleanup;
+      continue;
     }
 
     for (j = 0; j < artifacts_len; ++j) {

src/adapters/tgk_store_mem/tgk_store_mem.c

@@ -111,9 +111,12 @@ static bool amduat_tgk_store_mem_type_filter_match(
     amduat_tgk_edge_type_id_t type_id) {
   size_t i;
 
-  if (filter.types_len == 0 || filter.types == NULL) {
+  if (filter.types_len == 0) {
     return true;
   }
+  if (filter.types == NULL) {
+    return false;
+  }
   for (i = 0; i < filter.types_len; ++i) {
     if (filter.types[i] == type_id) {
       return true;