test: add memory leak check to LLM context size tests

Appends a call to assert_sqlite_memory_clean in three test cleanup sections to ensure no memory leaks occur after LLM context size error tests.

Author: andinux

tests/c/unittest.c

@@ -859,6 +859,7 @@ static int test_chat_system_prompt_new_chat(const test_env *env) {
     if (context_created) exec_expect_ok(env, db, "SELECT llm_context_free();");
     if (model_loaded) exec_expect_ok(env, db, "SELECT llm_model_free();");
     if (db) sqlite3_close(db);
+    if (status == 0) status = assert_sqlite_memory_clean("llm_context_size_errors", env);
     return status;
 }
 
@@ -922,6 +923,7 @@ static int test_chat_system_prompt_replace_previous_prompt(const test_env *env)
     if (context_created) exec_expect_ok(env, db, "SELECT llm_context_free();");
     if (model_loaded) exec_expect_ok(env, db, "SELECT llm_model_free();");
     if (db) sqlite3_close(db);
+    if (status == 0) status = assert_sqlite_memory_clean("llm_context_size_errors", env);
     return status;
 }
 
@@ -1002,6 +1004,7 @@ static int test_chat_system_prompt_after_first_response(const test_env *env) {
     if (context_created) exec_expect_ok(env, db, "SELECT llm_context_free();");
     if (model_loaded) exec_expect_ok(env, db, "SELECT llm_model_free();");
     if (db) sqlite3_close(db);
+    if (status == 0) status = assert_sqlite_memory_clean("llm_context_size_errors", env);
     return status;
 }