fix: memory 工具 required 数组添加 type — 解决模型持续不传 type 参数问题

Ollama function calling 依赖 JSON Schema 的 required 数组判断参数必要性，
type 不在 required 中导致模型认为它是可选的，即使 error 提示了也不传。
将其加入 required 数组后，模型将被强制要求每次调用都提供 type 参数。

src/renderer/services/tool-registry.ts

@@ -367,7 +367,7 @@ export const TOOL_DEFINITIONS: ToolDefinition[] = [
 CRITICAL: For add action, you MUST include both "type" (fact/preference/rule) and "content" fields. If you omit them, the call will fail.`,
       parameters: {
         type: 'object',
-        required: ['action'],
+        required: ['action', 'type'],
         properties: {
           action: { type: 'string', enum: ['search', 'add', 'replace', 'remove', 'read_all'], description: 'Which operation to perform.' },
           query: { type: 'string', description: '[search] Keywords to search for.' },