fix(proxy): bypass timeout and retry configs when failover is disabled

When auto_failover_enabled is false, timeout and retry configurations
should not affect normal request flow. This change ensures:

- create_forwarder: passes 0 for all timeout/retry params when failover
  is disabled, effectively bypassing these checks
- streaming_timeout_config: returns 0 for both first_byte_timeout and
  idle_timeout when failover is disabled

This prevents unnecessary timeout errors and retry attempts when users
have explicitly disabled the failover feature.

src-tauri/src/proxy/handler_context.rs

@@ -148,18 +148,40 @@ impl RequestContext {
     /// 创建 RequestForwarder
     ///
     /// 使用共享的 ProviderRouter，确保熔断器状态跨请求保持
+    ///
+    /// 配置生效规则：
+    /// - 故障转移开启：超时配置和重试次数正常生效（0 表示禁用超时/不重试直接故障转移）
+    /// - 故障转移关闭：超时配置和重试次数不生效（全部传入 0）
     pub fn create_forwarder(&self, state: &ProxyState) -> RequestForwarder {
+        let (non_streaming_timeout, max_retries, first_byte_timeout, idle_timeout) =
+            if self.app_config.auto_failover_enabled {
+                // 故障转移开启：使用配置的值（0 = 禁用超时 / 不重试直接故障转移）
+                (
+                    self.app_config.non_streaming_timeout as u64,
+                    self.app_config.max_retries as u8,
+                    self.app_config.streaming_first_byte_timeout as u64,
+                    self.app_config.streaming_idle_timeout as u64,
+                )
+            } else {
+                // 故障转移关闭：不启用超时和重试配置
+                log::info!(
+                    "[{}] Failover disabled, timeout and retry configs are bypassed",
+                    self.tag
+                );
+                (0, 0, 0, 0)
+            };
+
         RequestForwarder::new(
             state.provider_router.clone(),
-            self.app_config.non_streaming_timeout as u64,
-            self.app_config.max_retries as u8,
+            non_streaming_timeout,
+            max_retries,
             state.status.clone(),
             state.current_providers.clone(),
             state.failover_manager.clone(),
             state.app_handle.clone(),
             self.current_provider_id.clone(),
-            self.app_config.streaming_first_byte_timeout as u64,
-            self.app_config.streaming_idle_timeout as u64,
+            first_byte_timeout,
+            idle_timeout,
         )
     }
 
@@ -177,11 +199,24 @@ impl RequestContext {
     }
 
     /// 获取流式超时配置
+    ///
+    /// 配置生效规则：
+    /// - 故障转移开启：返回配置的值（0 表示禁用超时检查）
+    /// - 故障转移关闭：返回 0（禁用超时检查）
     #[inline]
     pub fn streaming_timeout_config(&self) -> StreamingTimeoutConfig {
-        StreamingTimeoutConfig {
-            first_byte_timeout: self.app_config.streaming_first_byte_timeout as u64,
-            idle_timeout: self.app_config.streaming_idle_timeout as u64,
+        if self.app_config.auto_failover_enabled {
+            // 故障转移开启：使用配置的值（0 = 禁用超时）
+            StreamingTimeoutConfig {
+                first_byte_timeout: self.app_config.streaming_first_byte_timeout as u64,
+                idle_timeout: self.app_config.streaming_idle_timeout as u64,
+            }
+        } else {
+            // 故障转移关闭：禁用流式超时检查
+            StreamingTimeoutConfig {
+                first_byte_timeout: 0,
+                idle_timeout: 0,
+            }
         }
     }
 }