docs: make English the default docs language and fix link paths

docs/tools/memory.mdx

@@ -1,43 +1,43 @@
 ---
-title: memory - 记忆与知识
-description: 搜索和读取长期记忆及知识库文件
+title: memory - Memory & Knowledge
+description: Search and read long-term memory and knowledge base files
 ---
 
-记忆工具包含两个子工具：`memory_search`（搜索记忆）和 `memory_get`（读取记忆或知识文件）。
+The memory tool contains two sub-tools: `memory_search` (search memory) and `memory_get` (read memory or knowledge files).
 
-当 [知识库](/knowledge) 功能开启时，这两个工具同时支持访问 `memory/` 和 `knowledge/` 目录下的文件。
+When the [knowledge base](/knowledge) feature is enabled, both tools also support accessing files under the `knowledge/` directory.
 
-## 依赖
+## Dependencies
 
-无额外依赖，默认可用。由 Agent Core 的记忆系统管理。
+No extra dependencies, available by default. Managed by the Agent Core memory system.
 
 ## memory_search
 
-搜索历史记忆和知识库内容，支持关键词和向量混合检索。
+Search historical memory and knowledge base content with hybrid keyword and vector retrieval.
 
-| 参数 | 类型 | 必填 | 说明 |
+| Parameter | Type | Required | Description |
 | --- | --- | --- | --- |
-| `query` | string | 是 | 搜索查询 |
+| `query` | string | Yes | Search query |
 
 ## memory_get
 
-读取特定记忆文件或知识库文件的内容。
+Read the content of a specific memory or knowledge file.
 
-| 参数 | 类型 | 必填 | 说明 |
+| Parameter | Type | Required | Description |
 | --- | --- | --- | --- |
-| `path` | string | 是 | 文件的相对路径（如 `MEMORY.md`、`memory/2026-01-01.md`、`knowledge/concepts/rag.md`） |
-| `start_line` | integer | 否 | 起始行号 |
-| `end_line` | integer | 否 | 结束行号 |
+| `path` | string | Yes | Relative path to the file (e.g. `MEMORY.md`, `memory/2026-01-01.md`, `knowledge/concepts/rag.md`) |
+| `start_line` | integer | No | Start line number |
+| `end_line` | integer | No | End line number |
 
-## 工作方式
+## How It Works
 
-Agent 会在以下场景自动调用记忆工具：
+The Agent automatically invokes memory tools in these scenarios:
 
-- 用户分享重要信息时 → 存储到记忆
-- 需要参考历史信息时 → 搜索相关记忆
-- 对话达到一定长度时 → 提取摘要存储
-- 讨论到专业知识时 → 检索知识库中的相关页面
+- When the user shares important information → stores to memory
+- When historical context is needed → searches relevant memory
+- When conversation reaches a certain length → extracts summary for storage
+- When discussing domain knowledge → retrieves relevant pages from the knowledge base
 
 <Note>
-  当 `knowledge` 配置为 `false` 时，工具的描述和搜索范围会自动调整为仅包含记忆文件。
+  When `knowledge` is set to `false` in config, the tool descriptions and search scope automatically adjust to include only memory files.
 </Note>