Async config loading (#18022)

Parts of config will come from executor. Prepare for that by making
config loading methods async.

codex-rs/app-server/src/codex_message_processor.rs

@@ -2442,6 +2442,7 @@ impl CodexMessageProcessor {
                 ))
         {
             let trust_target = resolve_root_git_project_for_trust(config.cwd.as_path())
+                .await
                 .unwrap_or_else(|| config.cwd.to_path_buf());
             let cli_overrides_with_trust;
             let cli_overrides_for_reload = if let Err(err) =

codex-rs/app-server/src/in_process.rs

@@ -716,6 +716,7 @@ mod tests {
         match ConfigBuilder::default().build().await {
             Ok(config) => config,
             Err(_) => Config::load_default_with_cli_overrides(Vec::new())
+                .await
                 .expect("default config should load"),
         }
     }

codex-rs/app-server/src/lib.rs

@@ -432,12 +432,14 @@ pub async fn run_main_with_transport(
         Err(err) => {
             let message = config_warning_from_error("Invalid configuration; using defaults.", &err);
             config_warnings.push(message);
-            Config::load_default_with_cli_overrides(cli_kv_overrides.clone()).map_err(|e| {
-                std::io::Error::new(
-                    ErrorKind::InvalidData,
-                    format!("error loading default config after config error: {e}"),
-                )
-            })?
+            Config::load_default_with_cli_overrides(cli_kv_overrides.clone())
+                .await
+                .map_err(|e| {
+                    std::io::Error::new(
+                        ErrorKind::InvalidData,
+                        format!("error loading default config after config error: {e}"),
+                    )
+                })?
         }
     };