feat: custom app icon (#7196)

Co-authored-by: crazywoola <427733928@qq.com>

web/types/app.ts

@@ -291,12 +291,16 @@ export type SiteConfig = {
   /** Custom Disclaimer */
   custom_disclaimer: string
 
+  icon_type: AppIconType | null
   icon: string
-  icon_background: string
+  icon_background: string | null
+  icon_url: string | null
 
   show_workflow_steps: boolean
 }
 
+export type AppIconType = 'image' | 'emoji'
+
 /**
  * App
  */
@@ -308,10 +312,17 @@ export type App = {
   /** Description */
   description: string
 
-  /** Icon */
+  /**
+   * Icon Type
+   * @default 'emoji'
+  */
+  icon_type: AppIconType | null
+  /** Icon, stores file ID if icon_type is 'image' */
   icon: string
-  /** Icon Background */
-  icon_background: string
+  /** Icon Background, only available when icon_type is null or 'emoji' */
+  icon_background: string | null
+  /** Icon URL, only available when icon_type is 'image' */
+  icon_url: string | null
 
   /** Mode */
   mode: AppMode