feat(proxy): add isFullUrl toggle for full API endpoint mode

- provider.rs/types.ts: add is_full_url field to ProviderMeta
- forwarder.rs: when isFullUrl is set, use base_url directly instead of
  appending endpoint path; also handle query passthrough and strip
  beta=true when transforming to /v1/chat/completions
- EndpointField.tsx: add Link2 icon toggle button for full URL mode
- ClaudeFormFields.tsx: pass through isFullUrl/onFullUrlChange props
- ProviderForm.tsx: manage localIsFullUrl state, persist to meta on save
- useProviderActions.ts: block switching to isFullUrl or openai_chat
  providers when proxy is not running, show warning toast
- App.tsx: pass isProxyRunning to useProviderActions
- i18n: add fullUrlEnabled/fullUrlDisabled/fullUrlHint and
  proxyRequiredForSwitch translations for zh/en/ja

src-tauri/src/provider.rs

@@ -240,6 +240,9 @@ pub struct ProviderMeta {
     /// - "ANTHROPIC_API_KEY": 少数供应商需要原生 API Key
     #[serde(rename = "apiKeyField", skip_serializing_if = "Option::is_none")]
     pub api_key_field: Option<String>,
+    /// 是否将 base_url 视为完整 API 端点（不拼接 endpoint 路径）
+    #[serde(rename = "isFullUrl", skip_serializing_if = "Option::is_none")]
+    pub is_full_url: Option<bool>,
 }
 
 impl ProviderManager {

src-tauri/src/proxy/forwarder.rs

@@ -749,15 +749,55 @@ impl RequestForwarder {
         // 检查是否需要格式转换
         let needs_transform = adapter.needs_transform(provider);
 
-        let effective_endpoint =
-            if needs_transform && adapter.name() == "Claude" && endpoint == "/v1/messages" {
-                "/v1/chat/completions"
+        // 检查 isFullUrl 模式：直接使用 base_url 作为完整 API 端点
+        let is_full_url = provider
+            .meta
+            .as_ref()
+            .and_then(|m| m.is_full_url)
+            .unwrap_or(false);
+
+        let url = if is_full_url {
+            // 全链接模式：直接使用 base_url，将客户端 query 追加
+            let query = endpoint.split_once('?').map(|(_, q)| q);
+            match query {
+                Some(q) if !q.is_empty() => {
+                    if base_url.contains('?') {
+                        format!("{base_url}&{q}")
+                    } else {
+                        format!("{base_url}?{q}")
+                    }
+                }
+                _ => base_url.clone(),
+            }
+        } else {
+            // 正常模式：endpoint 可能带 query string，需拆分路径和参数
+            let effective_endpoint: String = if needs_transform && adapter.name() == "Claude" {
+                let (path, query) = match endpoint.split_once('?') {
+                    Some((p, q)) => (p, Some(q)),
+                    None => (endpoint, None),
+                };
+                if path == "/v1/messages" || path == "/claude/v1/messages" {
+                    // 转换到 chat/completions 时剥离 beta=true（Anthropic 专有参数）
+                    let filtered = query.map(|q| {
+                        q.split('&')
+                            .filter(|p| !p.starts_with("beta="))
+                            .collect::<Vec<_>>()
+                            .join("&")
+                    });
+                    match filtered.as_deref() {
+                        Some(q) if !q.is_empty() => format!("/v1/chat/completions?{q}"),
+                        _ => "/v1/chat/completions".to_string(),
+                    }
+                } else {
+                    endpoint.to_string()
+                }
             } else {
-                endpoint
+                endpoint.to_string()
             };
 
-        // 使用适配器构建 URL
-        let url = adapter.build_url(&base_url, effective_endpoint);
+            // 使用适配器构建 URL
+            adapter.build_url(&base_url, &effective_endpoint)
+        };
 
         // 应用模型映射（独立于格式转换）
         let (mapped_body, _original_model, _mapped_model) =