[codex] Enable apply_patch freeform by default (#21687)

## Summary
- enable `apply_patch_freeform` by default in the feature registry

## Why
- make the freeform `apply_patch` tool available by default when model
metadata does not explicitly opt into another mode

## Validation
- `just fmt`
- did not run tests

---------

Co-authored-by: Codex <noreply@openai.com>

codex-rs/tools/src/tool_config.rs

@@ -222,7 +222,7 @@ impl ToolsConfig {
         let apply_patch_tool_type = match model_info.apply_patch_tool_type {
             Some(ApplyPatchToolType::Freeform) => Some(ApplyPatchToolType::Freeform),
             Some(ApplyPatchToolType::Function) => Some(ApplyPatchToolType::Function),
-            None => include_apply_patch_tool.then_some(ApplyPatchToolType::Freeform),
+            None => include_apply_patch_tool.then_some(ApplyPatchToolType::Function),
         };
 
         let agent_jobs_worker_tools = include_agent_jobs

codex-rs/tools/src/tool_config_tests.rs

@@ -4,6 +4,7 @@ use codex_features::Features;
 use codex_protocol::config_types::WebSearchMode;
 use codex_protocol::config_types::WindowsSandboxLevel;
 use codex_protocol::models::PermissionProfile;
+use codex_protocol::openai_models::ApplyPatchToolType;
 use codex_protocol::openai_models::ConfigShellToolType;
 use codex_protocol::openai_models::InputModality;
 use codex_protocol::openai_models::ModelInfo;
@@ -154,6 +155,29 @@ fn shell_zsh_fork_prefers_shell_command_over_unified_exec() {
     );
 }
 
+#[test]
+fn fallback_apply_patch_models_use_function_tool_by_default() {
+    let model_info = model_info();
+    let features = Features::with_defaults();
+
+    let available_models = Vec::new();
+    let tools_config = ToolsConfig::new(&ToolsConfigParams {
+        model_info: &model_info,
+        available_models: &available_models,
+        features: &features,
+        image_generation_tool_auth_allowed: true,
+        web_search_mode: Some(WebSearchMode::Cached),
+        session_source: SessionSource::Cli,
+        permission_profile: &PermissionProfile::Disabled,
+        windows_sandbox_level: WindowsSandboxLevel::Disabled,
+    });
+
+    assert_eq!(
+        tools_config.apply_patch_tool_type,
+        Some(ApplyPatchToolType::Function)
+    );
+}
+
 #[test]
 fn subagents_keep_request_user_input_config_and_agent_jobs_workers_opt_in_by_label() {
     let model_info = model_info();