fix: 拦截 ExecuteExtraTool 直接调用未搜索的延迟工具

模型在未通过 SearchExtraTools 发现工具的情况下直接调用 ExecuteExtraTool，
因不知道工具 schema 导致参数错误（如 libraryName: undefined）。

双重修复：
1. ExecuteTool.call() 添加服务端拦截：检查目标 deferred 工具是否已被发现
2. 更新 <available-deferred-tools> 系统提示：要求先搜索再执行

Co-Authored-By: glm-5-turbo <zai-org@claude-code-best.win>

src/services/api/claude.ts

@@ -1396,7 +1396,7 @@ async function* queryModel(
       messagesForAPI = [
         ...messagesForAPI,
         createUserMessage({
-          content: `<system-reminder>\n<available-deferred-tools>\n${deferredToolList}\n</available-deferred-tools>\nTo invoke any tool listed above, use ExecuteExtraTool with {"tool_name": "<name>", "params": {...}}. This is the ONLY way to call deferred tools — do not read source code or analyze implementation, just call ExecuteExtraTool directly.\n</system-reminder>`,
+          content: `<system-reminder>\n<available-deferred-tools>\n${deferredToolList}\n</available-deferred-tools>\nIMPORTANT: These tools are deferred-loading. You MUST first discover a tool via SearchExtraTools before invoking it with ExecuteExtraTool. Do NOT call ExecuteExtraTool directly — it will fail if the tool has not been discovered.\n\nSteps:\n1. SearchExtraTools("select:<tool_name>") — discover the tool and its schema\n2. ExecuteExtraTool({"tool_name": "<name>", "params": {...}}) — invoke it with correct parameters\n</system-reminder>`,
           isMeta: true,
         }),
       ]