Add Codex Chat-to-Responses bridge

- Add Codex provider API format selection and model mapping for Chat-only upstreams.
- Convert Codex Responses requests to Chat Completions and rebuild Chat responses as Responses output.
- Preserve reasoning_content across non-streaming, streaming, tool calls, and previous_response_id follow-ups.
- Add a bounded Codex Chat history cache for restoring tool calls before tool outputs.
- Cover Chat bridge, compact routing, streaming, and history recovery with focused tests.

src-tauri/src/proxy/server.rs

@@ -9,8 +9,12 @@
 //! a direct (non-proxied) CLI request.
 
 use super::{
-    failover_switch::FailoverSwitchManager, handlers, log_codes::srv as log_srv,
-    provider_router::ProviderRouter, providers::gemini_shadow::GeminiShadowStore, types::*,
+    failover_switch::FailoverSwitchManager,
+    handlers,
+    log_codes::srv as log_srv,
+    provider_router::ProviderRouter,
+    providers::{codex_chat_history::CodexChatHistoryStore, gemini_shadow::GeminiShadowStore},
+    types::*,
     ProxyError,
 };
 use crate::database::Database;
@@ -38,6 +42,8 @@ pub struct ProxyState {
     pub provider_router: Arc<ProviderRouter>,
     /// Gemini Native shadow state，用于 thoughtSignature / tool call 回放
     pub gemini_shadow: Arc<GeminiShadowStore>,
+    /// Codex Chat bridge history，用于恢复 previous_response_id 指向的 tool call
+    pub codex_chat_history: Arc<CodexChatHistoryStore>,
     /// AppHandle，用于发射事件和更新托盘菜单
     pub app_handle: Option<tauri::AppHandle>,
     /// 故障转移切换管理器
@@ -72,6 +78,7 @@ impl ProxyServer {
             current_providers: Arc::new(RwLock::new(std::collections::HashMap::new())),
             provider_router,
             gemini_shadow: Arc::new(GeminiShadowStore::default()),
+            codex_chat_history: Arc::new(CodexChatHistoryStore::default()),
             app_handle,
             failover_manager,
         };