chore(features) codex dependencies feat (#17960)

## Summary
Setting this up

## Testing
- [x] Unit tests pass

codex-rs/features/src/lib.rs

@@ -191,6 +191,8 @@ pub enum Feature {
     ResponsesWebsocketsV2,
     /// Use the agent identity registration flow for ChatGPT-authenticated sessions.
     UseAgentIdentity,
+    /// Enable workspace dependency support.
+    WorkspaceDependencies,
 }
 
 impl Feature {
@@ -929,6 +931,12 @@ pub const FEATURES: &[FeatureSpec] = &[
         stage: Stage::UnderDevelopment,
         default_enabled: false,
     },
+    FeatureSpec {
+        id: Feature::WorkspaceDependencies,
+        key: "workspace_dependencies",
+        stage: Stage::Stable,
+        default_enabled: true,
+    },
 ];
 
 pub fn unstable_features_warning_event(