test-lfm2: skip needle test suite for legacy parser

The legacy lfm2 parser requires a "force json schema." marker in the
system message to enable tool call grammar. Skip run_template_test_suite
for legacy mode since it uses generic inputs without this marker.

The explicit tests in test-lfm2.cpp still run and cover the legacy parser
behavior with the proper marker.

Enables: lfm2:legacy

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: ochafik

tests/chat-parsers/test-lfm2.cpp

@@ -33,7 +33,10 @@ void test_lfm2_parser(chat_parser_impl impl)
 
     auto tmpls = read_templates(template_caps.jinja_path);
 
-    run_template_test_suite(impl, template_caps, tmpls);
+    // Skip needle test suite for legacy - legacy parser requires "force json schema." marker in system message
+    if (impl != chat_parser_impl::LEGACY) {
+        run_template_test_suite(impl, template_caps, tmpls);
+    }
 
 
     auto inputs_tools_forced_json_schema = std::invoke([&]() -> common_chat_templates_inputs {

tests/test-chat.cpp

@@ -1420,8 +1420,7 @@ static void test_chat_parsers()
     // Note: skips run_template_test_suite due to Kimi's reasoning message splitting
     test_chat_parser(test_status::Enabled, "kimi_k2", chat_parser_impl::EXPERIMENTAL, test_kimi_k2_parser);
 
-    // TODO
-    test_chat_parser(test_status::Disabled, "lfm2", chat_parser_impl::LEGACY, test_lfm2_parser);
+    test_chat_parser(test_status::Enabled, "lfm2", chat_parser_impl::LEGACY, test_lfm2_parser);
     // TODO
     test_chat_parser(test_status::Disabled, "lfm2", chat_parser_impl::EXPERIMENTAL, test_lfm2_parser);