feat(search): 自定义引擎支持图标地址（png / svg）

- settings.search.engines[] 新增 icon：空=品牌图标/通用地球，'/' 开头走托管目录，或 http(s) 链接
- 后端校验图标地址（空 / 托管路径 / http(s)，≤500 字符）
- 后台每张引擎卡加「图标地址」输入；前后台都用组件库 EngineIcon 的 src（<img> 渲染，SVG 静态不执行脚本）
- @stash/ui 0.3.4

stash-web/src/AppNext.tsx

@@ -69,7 +69,7 @@ type Route =
   | { kind: 'item'; key: string; itemId: string }
   | { kind: 'api' }
 
-const INTERNAL_SEARCH = { id: 'internal', name: '站内搜索', url: '' } as const
+const INTERNAL_SEARCH = { id: 'internal', name: '站内搜索', url: '', icon: '' } as const
 
 const SEARCH_ENGINE_KEY = 'stash-search-engine'
 
@@ -362,7 +362,12 @@ export default function AppNext() {
     INTERNAL_SEARCH,
     ...site.search.engines
       .filter((engine) => engine.enabled)
-      .map((engine) => ({ id: engine.id, name: engine.name, url: engine.url })),
+      .map((engine) => ({
+        id: engine.id,
+        name: engine.name,
+        url: engine.url,
+        icon: engine.icon ?? '',
+      })),
   ]
   const searchEngine =
     searchEngines.find((engine) => engine.id === searchEngineId) ??
@@ -930,7 +935,7 @@ export default function AppNext() {
                 }
                 onClick={() => setEngineOpen((open) => !open)}
               >
-                <EngineIcon name={searchEngine.id} size={14} />
+                <EngineIcon name={searchEngine.id} src={searchEngine.icon} size={14} />
                 <span>{searchEngine.name}</span>
               </button>
 
@@ -977,7 +982,7 @@ export default function AppNext() {
                           className={`engine-option${engine.id === searchEngine.id ? ' is-active' : ''}`}
                           onClick={() => chooseEngine(engine.id)}
                         >
-                          <EngineIcon name={engine.id} size={18} />
+                          <EngineIcon name={engine.id} src={engine.icon} size={18} />
                           <span>{engine.name}</span>
                         </button>
                       ))}

stash-web/src/components/admin/AdminNext.tsx

@@ -2102,6 +2102,7 @@ function SearchPanel({
           id: `custom-${Date.now().toString(36)}`,
           name: '新搜索引擎',
           url: '',
+          icon: '',
           enabled: true,
         },
       ],
@@ -2147,7 +2148,7 @@ function SearchPanel({
             key={engine.id}
           >
             <div className="search-engine-head">
-              <EngineIcon name={engine.id} size={18} />
+              <EngineIcon name={engine.id} src={engine.icon} size={18} />
               <Text strong>{engine.name || engine.id}</Text>
               <div className="search-engine-actions">
                 <Switch
@@ -2178,6 +2179,18 @@ function SearchPanel({
                 />
               </FormField>
             </div>
+            <FormField
+              label="图标地址"
+              htmlFor={`search-icon-${engine.id}`}
+              hint="png / svg；留空用默认图标（内置品牌或通用地球），站内图片放 public/ 后填 /xxx.svg"
+            >
+              <Input
+                id={`search-icon-${engine.id}`}
+                value={engine.icon ?? ''}
+                placeholder="/icons/xxx.svg 或 https://…"
+                onChange={(event) => updateEngine(engine.id, { icon: event.target.value })}
+              />
+            </FormField>
           </div>
         ))}
       </div>

stash-web/src/settings.ts

@@ -84,6 +84,8 @@ export type SearchEngineSettings = {
   name: string
   /** 搜索地址模板，用 {query} 表示关键词 */
   url: string
+  /** 自定义图标地址（png / svg）；空表示用品牌图标或通用地球 */
+  icon: string
   enabled: boolean
 }
 
@@ -99,30 +101,35 @@ export const DEFAULT_SEARCH_ENGINES: SearchEngineSettings[] = [
     id: 'google',
     name: 'Google',
     url: 'https://www.google.com/search?q={query}',
+    icon: '',
     enabled: true,
   },
   {
     id: 'bing',
     name: 'Bing',
     url: 'https://www.bing.com/search?q={query}',
+    icon: '',
     enabled: true,
   },
   {
     id: 'baidu',
     name: '百度',
     url: 'https://www.baidu.com/s?wd={query}',
+    icon: '',
     enabled: true,
   },
   {
     id: 'sogou',
     name: '搜狗',
     url: 'https://www.sogou.com/web?query={query}',
+    icon: '',
     enabled: true,
   },
   {
     id: '360',
     name: '360',
     url: 'https://www.so.com/s?q={query}',
+    icon: '',
     enabled: true,
   },
 ]