fix(proxy): preserve URL query/fragment and improve error handling

Extract shared URL utilities to handle query strings and fragments correctly.
Add race condition fix for URL preview, improve proxy toggle error feedback,
and support Codex chat format proxy endpoint.

src-tauri/src/proxy/url_builder.rs

@@ -3,6 +3,7 @@
 //! 提供统一的 URL 构建逻辑，供前端预览和后端代理使用。
 
 use crate::app_config::AppType;
+use crate::proxy::url_utils::{dedup_v1_v1_boundary_safe, split_url_suffix};
 use serde::{Deserialize, Serialize};
 
 /// URL 预览结果
@@ -46,12 +47,33 @@ impl ApiPathPatterns {
         }
     }
 
-    fn for_codex(_api_format: Option<&str>) -> Self {
-        // Codex 只支持 /responses 端点
-        Self {
-            direct_endpoint: "/responses",
-            proxy_endpoint: "/responses",
-            full_url_patterns: &["/v1/responses", "/responses"],
+    fn for_codex(api_format: Option<&str>) -> Self {
+        // Codex:
+        // - Direct mode (Codex CLI) hard-codes Responses API: `/responses`
+        // - Proxy mode might target different upstream formats (e.g. Chat Completions)
+        let is_chat = matches!(api_format, Some("chat"));
+        if is_chat {
+            Self {
+                direct_endpoint: "/responses",
+                proxy_endpoint: "/v1/chat/completions",
+                full_url_patterns: &[
+                    "/v1/responses",
+                    "/responses",
+                    "/v1/chat/completions",
+                    "/chat/completions",
+                ],
+            }
+        } else {
+            Self {
+                direct_endpoint: "/responses",
+                proxy_endpoint: "/responses",
+                full_url_patterns: &[
+                    "/v1/responses",
+                    "/responses",
+                    "/v1/chat/completions",
+                    "/chat/completions",
+                ],
+            }
         }
     }
 
@@ -66,9 +88,8 @@ impl ApiPathPatterns {
 
 /// 检测 URL 是否以指定的 API 路径结尾
 fn url_ends_with_api_path(url: &str, patterns: &[&str]) -> bool {
-    let trimmed = url.trim_end_matches('/').to_lowercase();
-    // 移除查询参数
-    let path_part = trimmed.split('?').next().unwrap_or(&trimmed);
+    let (base, _) = split_url_suffix(url);
+    let path_part = base.trim_end_matches('/').to_lowercase();
     patterns
         .iter()
         .any(|pattern| path_part.ends_with(&pattern.to_lowercase()))
@@ -78,34 +99,31 @@ fn url_ends_with_api_path(url: &str, patterns: &[&str]) -> bool {
 ///
 /// 始终将 endpoint 拼接到 base_url 后面，不做任何智能检测或去重。
 fn build_direct_url(base_url: &str, endpoint: &str) -> String {
-    let base_trimmed = base_url.trim_end_matches('/');
+    let (base, suffix) = split_url_suffix(base_url);
+    let base_trimmed = base.trim_end_matches('/');
     let endpoint_trimmed = endpoint.trim_start_matches('/');
 
     // 直接拼接，不做任何去重
-    format!("{base_trimmed}/{endpoint_trimmed}")
+    format!("{base_trimmed}/{endpoint_trimmed}{suffix}")
 }
 
 /// 智能构建 URL（用于代理地址）
 ///
 /// 如果 base_url 已经以 API 路径结尾，直接返回；否则追加 endpoint。
 pub fn build_smart_url(base_url: &str, endpoint: &str, full_url_patterns: &[&str]) -> String {
-    let base_trimmed = base_url.trim_end_matches('/');
+    let (base, suffix) = split_url_suffix(base_url);
+    let base_trimmed = base.trim_end_matches('/');
     let endpoint_trimmed = endpoint.trim_start_matches('/');
 
     // 检测 base_url 是否已经以 API 路径结尾
     if url_ends_with_api_path(base_trimmed, full_url_patterns) {
-        return base_trimmed.to_string();
+        return format!("{base_trimmed}{suffix}");
     }
 
     // 拼接 URL
-    let mut url = format!("{base_trimmed}/{endpoint_trimmed}");
-
-    // 去重 /v1/v1
-    while url.contains("/v1/v1") {
-        url = url.replace("/v1/v1", "/v1");
-    }
-
-    url
+    let url = format!("{base_trimmed}/{endpoint_trimmed}");
+    let url = dedup_v1_v1_boundary_safe(url);
+    format!("{url}{suffix}")
 }
 
 /// 构建 URL 预览
@@ -239,6 +257,17 @@ mod tests {
         assert!(!preview.is_full_url);
     }
 
+    #[test]
+    fn test_build_url_preview_codex_chat_proxy_endpoint() {
+        let preview = build_url_preview(&AppType::Codex, "https://api.openai.com", Some("chat"));
+        assert_eq!(preview.direct_url, "https://api.openai.com/responses");
+        assert_eq!(
+            preview.proxy_url,
+            "https://api.openai.com/v1/chat/completions"
+        );
+        assert!(!preview.is_full_url);
+    }
+
     #[test]
     fn test_build_url_preview_codex_full_url() {
         // 全链接时：直连会硬拼接后缀，代理保持原地址
@@ -315,6 +344,38 @@ mod tests {
         assert_eq!(preview.proxy_url, "https://api.example.com/v1/messages");
     }
 
+    #[test]
+    fn test_query_suffix_preserved_in_preview() {
+        let preview = build_url_preview(
+            &AppType::Claude,
+            "https://api.example.com?beta=true",
+            Some("anthropic"),
+        );
+        assert_eq!(
+            preview.direct_url,
+            "https://api.example.com/v1/messages?beta=true"
+        );
+        assert_eq!(
+            preview.proxy_url,
+            "https://api.example.com/v1/messages?beta=true"
+        );
+        assert!(!preview.is_full_url);
+    }
+
+    #[test]
+    fn test_fragment_suffix_preserved_and_full_url_detected() {
+        let preview = build_url_preview(
+            &AppType::Claude,
+            "https://api.example.com/v1/messages#frag",
+            Some("anthropic"),
+        );
+        assert_eq!(
+            preview.proxy_url,
+            "https://api.example.com/v1/messages#frag"
+        );
+        assert!(preview.is_full_url);
+    }
+
     #[test]
     fn test_full_url_detection_by_api_format() {
         // anthropic 格式：只有 /messages 结尾才是全链接