refactor(config): 将AI配置逻辑迁移至统一的状态管理store

- 移除独立的ai-config.ts文件，将其功能整合到use-config-store
- 更新所有组件导入路径从 "@/lib/ai-config" 到 "@/stores/use-config-store"
- 实现云端渠道和本地直连两种配置模式的支持
- 添加模型渠道配置管理和API请求代理转发功能
- 统一配置验证逻辑和有效配置获取方法
- 更新组件中使用的配置状态钩子和API调用方式

handler/ai.go

@@ -0,0 +1,113 @@
+package handler
+
+import (
+	"bytes"
+	"encoding/json"
+	"io"
+	"mime"
+	"mime/multipart"
+	"net/http"
+	"strings"
+
+	"github.com/basketikun/infinite-canvas/service"
+)
+
+func AIImagesGenerations(w http.ResponseWriter, r *http.Request) {
+	proxyAIRequest(w, r, "/images/generations")
+}
+
+func AIImagesEdits(w http.ResponseWriter, r *http.Request) {
+	proxyAIRequest(w, r, "/images/edits")
+}
+
+func AIChatCompletions(w http.ResponseWriter, r *http.Request) {
+	proxyAIRequest(w, r, "/chat/completions")
+}
+
+func proxyAIRequest(w http.ResponseWriter, r *http.Request, path string) {
+	body, contentType, modelName, err := readAIRequest(r)
+	if err != nil {
+		Fail(w, err.Error())
+		return
+	}
+	channel, err := service.SelectModelChannel(modelName)
+	if err != nil {
+		Fail(w, err.Error())
+		return
+	}
+	request, err := http.NewRequest(http.MethodPost, service.BuildModelChannelURL(channel, path), bytes.NewReader(body))
+	if err != nil {
+		Fail(w, err.Error())
+		return
+	}
+	request.Header.Set("Authorization", "Bearer "+channel.APIKey)
+	if contentType != "" {
+		request.Header.Set("Content-Type", contentType)
+	}
+	response, err := http.DefaultClient.Do(request)
+	if err != nil {
+		Fail(w, err.Error())
+		return
+	}
+	defer response.Body.Close()
+
+	for key, values := range response.Header {
+		if strings.EqualFold(key, "Content-Length") {
+			continue
+		}
+		for _, value := range values {
+			w.Header().Add(key, value)
+		}
+	}
+	w.WriteHeader(response.StatusCode)
+	_, _ = io.Copy(w, response.Body)
+}
+
+func readAIRequest(r *http.Request) ([]byte, string, string, error) {
+	contentType := r.Header.Get("Content-Type")
+	body, err := io.ReadAll(r.Body)
+	if err != nil {
+		return nil, "", "", err
+	}
+	modelName := ""
+	if strings.HasPrefix(contentType, "multipart/form-data") {
+		modelName = readMultipartModel(body, contentType)
+	} else {
+		var payload struct {
+			Model string `json:"model"`
+		}
+		_ = json.Unmarshal(body, &payload)
+		modelName = payload.Model
+	}
+	if strings.TrimSpace(modelName) == "" {
+		return nil, "", "", errMissingModel
+	}
+	return body, contentType, modelName, nil
+}
+
+func readMultipartModel(body []byte, contentType string) string {
+	_, params, err := mime.ParseMediaType(contentType)
+	if err != nil {
+		return ""
+	}
+	reader := multipart.NewReader(bytes.NewReader(body), params["boundary"])
+	form, err := reader.ReadForm(32 << 20)
+	if err != nil {
+		return ""
+	}
+	defer form.RemoveAll()
+	if values := form.Value["model"]; len(values) > 0 {
+		return values[0]
+	}
+	return ""
+}
+
+var errMissingModel = &aiError{"缺少模型名称"}
+
+type aiError struct {
+	message string
+}
+
+func (err *aiError) Error() string {
+	return err.message
+}