feat: add support for custom OpenAI endpoint path

- Introduced a new endpoint option for OpenAI integrations, allowing users to specify a custom path.
- Updated relevant components and validation logic to accommodate the new endpoint.
- Enhanced documentation and error messages to reflect the addition of the custom endpoint option.

frontend/src/views/ModelEditor.vue

@@ -17,6 +17,7 @@ import {
   isModelAdapterTestResultStale,
   normalizeModelAdapter,
   OPENAI_ENDPOINT_CHAT_COMPLETIONS,
+  OPENAI_ENDPOINT_CUSTOM,
   OPENAI_ENDPOINT_RESPONSES,
   OPENAI_EXTRA_PARAMS_DEFAULT_JSON,
   runModelAdapterTest,
@@ -50,6 +51,7 @@ const anthropicThinkingEffortOptions = [
 const openAIEndpointOptions = [
   { label: "/v1/responses", value: OPENAI_ENDPOINT_RESPONSES, icon: "icon-[mdi--api]" },
   { label: "/v1/chat/completions", value: OPENAI_ENDPOINT_CHAT_COMPLETIONS, icon: "icon-[mdi--message-text-outline]" },
+  { label: "自定义路径(请输入完整请求地址)", value: OPENAI_ENDPOINT_CUSTOM, icon: "icon-[mdi--pencil-outline]" },
 ];
 
 const editorIndex = ref(-1);
@@ -128,7 +130,7 @@ const fieldTips = {
   contextWindowTokens: "模型单次可接受的最大上下文 Token 数。留空时使用默认值。",
   reasoningEffort: "推理强度仅对部分支持 reasoning_effort 的模型生效，并不是所有模型都支持。越高通常越稳，但也可能更慢。",
   maxCompletionTokens: "单次回复允许生成的最大 Token 数。留空时使用默认值。",
-  openAIEndpoint: "OpenAI 兼容接口使用的协议端点。未选择时默认使用 /v1/responses。",
+  openAIEndpoint: "选择接口协议端点。选“自定义路径”时，请在接口地址栏填写完整请求地址（含 /chat/completions 或 /responses 路径后缀），系统会根据末段自动判断协议形态。",
   openAIExtraParams: "开启后会把 JSON 对象覆盖到 OpenAI 请求体。同名字段以这里为准。OpenAI service_tier 支持 auto、default、flex、scale、priority。",
   customHeaders: "开启后会把 JSON 对象覆盖到最终请求头。同名请求头以这里为准，值必须是字符串。",
   anthropicExtraParams: "开启后会把 JSON 对象覆盖到 Anthropic 请求体。同名字段以这里为准。",