Add OpenAI/LiteLLM provider support with settings UI

- Add openai/ provider module with translator, client, convert, request/response translators
- Add shared provider/ types (ConversationMessage, MessageRole, ProviderConfig enum)
- Wire OpenAI-compatible provider dispatch alongside Bedrock in response_stream.rs
- Add ai.openai.* settings (enabled, base_url, api_key, model, models)
- Add OpenAI/LiteLLM settings page with model fetch, picker, and config UI
- Extend model menu items and llms.rs to surface LiteLLM models
- Update WARP.md with OpenAI provider architecture docs

app/build.rs

@@ -169,7 +169,6 @@ fn add_features(target_family: &str, target_os: &str) {
     if env::var("PROFILE").ok().is_some_and(|val| val == "debug") {
         println!("cargo:rustc-cfg=feature=\"agent_mode_debug\"");
     }
-
 }
 
 fn build_and_link_sentry() {