fix: allow HTTP for configurable service endpoints

DeepSeek Harness and Weixin binding configuration rejected non-loopback HTTP endpoints even when users explicitly selected those internal services. Configurable endpoints now accept valid HTTP and HTTPS URLs without host-location restrictions, while retaining the required protocol and API-key checks.

Release note: 模型连接、DeepSeek Harness 与微信绑定现在可直接使用局域网或公网 HTTP/HTTPS 服务地址，不再强制公网 HTTPS 或本机回环地址。

src/main/deepseek-harness-host.test.ts

@@ -39,7 +39,7 @@ describe('controlled DeepSeek Harness host', () => {
         dshHome: 'C:\\controlled-dsh-home',
         skillPackages: []
       })
-    ).rejects.toThrow('secure OpenAI-compatible')
+    ).rejects.toThrow('HTTP or HTTPS OpenAI-compatible')
   })
 
   it('suppresses console payloads instead of contaminating stdout', () => {