fix(app-server) move windows world writable warning (#6916)

## Summary
Move the app-server warning into the process_new_conversation

## Testing
- [x] Tested locally

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

@@ -91,6 +91,7 @@ use codex_app_server_protocol::TurnStatus;
 use codex_app_server_protocol::UserInfoResponse;
 use codex_app_server_protocol::UserInput as V2UserInput;
 use codex_app_server_protocol::UserSavedConfig;
+use codex_app_server_protocol::WindowsWorldWritableWarningNotification;
 use codex_app_server_protocol::build_turns_from_event_msgs;
 use codex_backend_client::Client as BackendClient;
 use codex_core::AuthManager;
@@ -1239,7 +1240,7 @@ impl CodexMessageProcessor {
         let overrides = ConfigOverrides {
             model,
             config_profile: profile,
-            cwd: cwd.map(PathBuf::from),
+            cwd: cwd.clone().map(PathBuf::from),
             approval_policy,
             sandbox_mode,
             model_provider,
@@ -1254,7 +1255,7 @@ impl CodexMessageProcessor {
         // Persist windows sandbox feature.
         // TODO: persist default config in general.
         let mut cli_overrides = cli_overrides.unwrap_or_default();
-        if cfg!(target_os = "windows") && self.config.features.enabled(Feature::WindowsSandbox) {
+        if cfg!(windows) && self.config.features.enabled(Feature::WindowsSandbox) {
             cli_overrides.insert(
                 "features.enable_experimental_windows_sandbox".to_string(),
                 serde_json::json!(true),
@@ -1273,6 +1274,10 @@ impl CodexMessageProcessor {
                 return;
             }
         };
+        if cfg!(windows) && config.features.enabled(Feature::WindowsSandbox) {
+            self.handle_windows_world_writable_warning(config.cwd.clone())
+                .await;
+        }
 
         match self.conversation_manager.new_conversation(config).await {
             Ok(conversation_id) => {
@@ -1953,6 +1958,15 @@ impl CodexMessageProcessor {
                     include_apply_patch_tool,
                 } = overrides;
 
+                // Persist windows sandbox feature.
+                let mut cli_overrides = cli_overrides.unwrap_or_default();
+                if cfg!(windows) && self.config.features.enabled(Feature::WindowsSandbox) {
+                    cli_overrides.insert(
+                        "features.enable_experimental_windows_sandbox".to_string(),
+                        serde_json::json!(true),
+                    );
+                }
+
                 let overrides = ConfigOverrides {
                     model,
                     config_profile: profile,
@@ -1968,7 +1982,7 @@ impl CodexMessageProcessor {
                     ..Default::default()
                 };
 
-                derive_config_from_params(overrides, cli_overrides).await
+                derive_config_from_params(overrides, Some(cli_overrides)).await
             }
             None => Ok(self.config.as_ref().clone()),
         };
@@ -1983,6 +1997,10 @@ impl CodexMessageProcessor {
                 return;
             }
         };
+        if cfg!(windows) && config.features.enabled(Feature::WindowsSandbox) {
+            self.handle_windows_world_writable_warning(config.cwd.clone())
+                .await;
+        }
 
         let conversation_history = if let Some(path) = path {
             match RolloutRecorder::get_rollout_history(&path).await {
@@ -2841,6 +2859,53 @@ impl CodexMessageProcessor {
             Err(_) => None,
         }
     }
+
+    /// On Windows, when using the experimental sandbox, we need to warn the user about world-writable directories.
+    async fn handle_windows_world_writable_warning(&self, cwd: PathBuf) {
+        if !cfg!(windows) {
+            return;
+        }
+
+        if !self.config.features.enabled(Feature::WindowsSandbox) {
+            return;
+        }
+
+        if !matches!(
+            self.config.sandbox_policy,
+            codex_protocol::protocol::SandboxPolicy::WorkspaceWrite { .. }
+                | codex_protocol::protocol::SandboxPolicy::ReadOnly
+        ) {
+            return;
+        }
+
+        if self
+            .config
+            .notices
+            .hide_world_writable_warning
+            .unwrap_or(false)
+        {
+            return;
+        }
+
+        // This function is stubbed out to return None on non-Windows platforms
+        if let Some((sample_paths, extra_count, failed_scan)) =
+            codex_windows_sandbox::world_writable_warning_details(
+                self.config.codex_home.as_path(),
+                cwd,
+            )
+        {
+            tracing::warn!("world writable warning: {sample_paths:?} {extra_count} {failed_scan}");
+            self.outgoing
+                .send_server_notification(ServerNotification::WindowsWorldWritableWarning(
+                    WindowsWorldWritableWarningNotification {
+                        sample_paths,
+                        extra_count,
+                        failed_scan,
+                    },
+                ))
+                .await;
+        }
+    }
 }
 
 async fn derive_config_from_params(

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

@@ -11,14 +11,11 @@ use codex_app_server_protocol::JSONRPCErrorError;
 use codex_app_server_protocol::JSONRPCNotification;
 use codex_app_server_protocol::JSONRPCRequest;
 use codex_app_server_protocol::JSONRPCResponse;
-use codex_app_server_protocol::ServerNotification;
-use codex_app_server_protocol::WindowsWorldWritableWarningNotification;
 use codex_core::AuthManager;
 use codex_core::ConversationManager;
 use codex_core::config::Config;
 use codex_core::default_client::USER_AGENT_SUFFIX;
 use codex_core::default_client::get_codex_user_agent;
-use codex_core::features::Feature;
 use codex_feedback::CodexFeedback;
 use codex_protocol::protocol::SessionSource;
 use std::sync::Arc;
@@ -26,7 +23,6 @@ use std::sync::Arc;
 pub(crate) struct MessageProcessor {
     outgoing: Arc<OutgoingMessageSender>,
     codex_message_processor: CodexMessageProcessor,
-    config: Arc<Config>,
     initialized: bool,
 }
 
@@ -54,14 +50,13 @@ impl MessageProcessor {
             conversation_manager,
             outgoing.clone(),
             codex_linux_sandbox_exe,
-            config.clone(),
+            config,
             feedback,
         );
 
         Self {
             outgoing,
             codex_message_processor,
-            config,
             initialized: false,
         }
     }
@@ -122,7 +117,6 @@ impl MessageProcessor {
                     self.outgoing.send_response(request_id, response).await;
 
                     self.initialized = true;
-                    self.handle_windows_world_writable_warning().await;
 
                     return;
                 }
@@ -162,54 +156,4 @@ impl MessageProcessor {
     pub(crate) fn process_error(&mut self, err: JSONRPCError) {
         tracing::error!("<- error: {:?}", err);
     }
-
-    /// On Windows, when using the experimental sandbox, we need to warn the user about world-writable directories.
-    async fn handle_windows_world_writable_warning(&self) {
-        if !cfg!(windows) {
-            return;
-        }
-
-        if !self.config.features.enabled(Feature::WindowsSandbox) {
-            return;
-        }
-
-        if !matches!(
-            self.config.sandbox_policy,
-            codex_protocol::protocol::SandboxPolicy::WorkspaceWrite { .. }
-                | codex_protocol::protocol::SandboxPolicy::ReadOnly
-        ) {
-            return;
-        }
-
-        if self
-            .config
-            .notices
-            .hide_world_writable_warning
-            .unwrap_or(false)
-        {
-            return;
-        }
-
-        // This function is stubbed out to return None on non-Windows platforms
-        let cwd = match std::env::current_dir() {
-            Ok(cwd) => cwd,
-            Err(_) => return,
-        };
-        if let Some((sample_paths, extra_count, failed_scan)) =
-            codex_windows_sandbox::world_writable_warning_details(
-                self.config.codex_home.as_path(),
-                cwd,
-            )
-        {
-            self.outgoing
-                .send_server_notification(ServerNotification::WindowsWorldWritableWarning(
-                    WindowsWorldWritableWarningNotification {
-                        sample_paths,
-                        extra_count,
-                        failed_scan,
-                    },
-                ))
-                .await;
-        }
-    }
 }