Refactor API routes and controllers for improved structure and clarity

- Updated API route structure to remove versioning and consolidate endpoints.
- Refactored routing in `server.go` to use a unified `/api` prefix for all controllers.
- Added new `ChannelController`, `ConversationController`, and `MessageController` to handle specific API functionalities.
- Removed deprecated `OpenImContextMiddleware` and related logic.
- Enhanced channel validation logic in `ChannelService` and `ChannelRepository`.
- Updated frontend API calls to align with new endpoint structure.

internal/controllers/api/channel_controller.go

@@ -0,0 +1,34 @@
+package api
+
+import (
+	"cs-agent/internal/pkg/dto/response"
+	"cs-agent/internal/services"
+
+	"github.com/kataras/iris/v12"
+	"github.com/mlogclub/simple/web"
+)
+
+type ChannelController struct {
+	Ctx iris.Context
+}
+
+func (c *ChannelController) AnyConfig() *web.JsonResult {
+	channel := services.ChannelService.GetEnabledChannel(c.Ctx)
+	if channel == nil {
+		return web.JsonErrorMsg("接入渠道未初始化")
+	}
+	cfg, err := services.ChannelService.ParseWebChannelConfig(channel.ConfigJSON)
+	if err != nil {
+		return web.JsonErrorMsg("Web渠道配置不合法")
+	}
+
+	ret := response.WidgetConfigResponse{
+		ChannelID:  channel.ChannelID,
+		Title:      cfg.Title,
+		Subtitle:   cfg.Subtitle,
+		ThemeColor: cfg.ThemeColor,
+		Position:   cfg.Position,
+		Width:      cfg.Width,
+	}
+	return web.JsonData(ret)
+}