test(catalog): address CodeRabbit review comments

- Use unique temp path for SaveAndLoad test to avoid parallel collisions
- Add ASSERT_NE for each create_index call in GetTableIndexes
- Add explicit #include <cstdio> and <filesystem>

Author: poyrazK

tests/catalog_coverage_tests.cpp

@@ -5,7 +5,9 @@
 
 #include <gtest/gtest.h>
 
+#include <cstdio>
 #include <cstring>
+#include <filesystem>
 #include <vector>
 
 #include "catalog/catalog.hpp"
@@ -216,8 +218,10 @@ TEST(CatalogCoverageTests, GetTableIndexes) {
     oid_t tid = catalog->create_table("indexed_table", cols);
     ASSERT_NE(tid, 0);
 
-    catalog->create_index("idx1", tid, {0}, IndexType::BTree, false);
-    catalog->create_index("idx2", tid, {0}, IndexType::Hash, true);
+    oid_t idx1_id = catalog->create_index("idx1", tid, {0}, IndexType::BTree, false);
+    ASSERT_NE(idx1_id, 0);
+    oid_t idx2_id = catalog->create_index("idx2", tid, {0}, IndexType::Hash, true);
+    ASSERT_NE(idx2_id, 0);
 
     auto indexes = catalog->get_table_indexes(tid);
     EXPECT_EQ(indexes.size(), 2);
@@ -235,18 +239,23 @@ TEST(CatalogCoverageTests, SaveAndLoad) {
     std::vector<ColumnInfo> cols = {{"id", common::ValueType::TYPE_INT64, 0}};
     catalog->create_table("persisted_table", cols);
 
+    // Use unique temp path to avoid collisions in parallel runs
+    static int test_counter = 0;
+    std::string temp_filename = "/tmp/test_catalog_" + std::to_string(++test_counter) + ".bin";
+    std::filesystem::path temp_path(temp_filename);
+
     // Save catalog - should succeed
-    ASSERT_TRUE(catalog->save("/tmp/test_catalog.bin"));
+    ASSERT_TRUE(catalog->save(temp_path.string()));
 
     // Create new catalog and load - should succeed (returns true)
     auto loaded_catalog = Catalog::create();
-    ASSERT_TRUE(loaded_catalog->load("/tmp/test_catalog.bin"));
+    ASSERT_TRUE(loaded_catalog->load(temp_path.string()));
 
     // Note: Due to stub implementation, loaded catalog won't have the table
     // This test verifies the save/load cycle works without crashing
 
     // Cleanup
-    std::remove("/tmp/test_catalog.bin");
+    std::filesystem::remove(temp_path);
 }
 
 /**