feat: configure tiered web search providers (#64)

api-providers/web-search/_index.json

@@ -1,4 +1,4 @@
 {
   "description": "web_search 工具后端加载顺序索引",
-  "order": ["tavily", "serper"]
+  "order": ["tavily", "brave", "serper"]
 }

api-providers/web-search/brave.json

@@ -0,0 +1,35 @@
+{
+  "id": "brave",
+  "name": "Brave Search API",
+  "capability": "web_search",
+  "enabled": false,
+  "builtin": true,
+  "priority": 20,
+  "endpoint": "https://api.search.brave.com/res/v1/web/search",
+  "method": "GET",
+  "auth": {
+    "type": "header",
+    "headerName": "X-Subscription-Token",
+    "apiKeyRef": "brave"
+  },
+  "request": {
+    "headers": {
+      "Accept": "application/json",
+      "Accept-Encoding": "gzip"
+    },
+    "queryParams": {
+      "q": "${query}",
+      "count": "${maxResults}"
+    }
+  },
+  "response": {
+    "resultsPath": "web.results",
+    "item": {
+      "titlePath": "title",
+      "urlPath": "url",
+      "snippetPath": "description",
+      "pageAgePath": "page_age"
+    }
+  },
+  "timeoutMs": 10000
+}

api-providers/web-search/serper.json

@@ -4,7 +4,7 @@
   "capability": "web_search",
   "enabled": false,
   "builtin": true,
-  "priority": 20,
+  "priority": 30,
   "endpoint": "https://google.serper.dev/search",
   "method": "POST",
   "auth": { "type": "header", "headerName": "X-API-KEY", "apiKeyRef": "serper" },