feat: docs update

docs/en/tools/env-config.mdx

@@ -0,0 +1,38 @@
+---
+title: env_config - Environment
+description: Manage API keys and secrets
+---
+
+# env_config
+
+Manage environment variables (API keys and secrets) in the workspace `.env` file, with secure conversational updates. Built-in security protection and desensitization.
+
+## Dependencies
+
+| Dependency | Install Command |
+| --- | --- |
+| `python-dotenv` ≥ 1.0.0 | `pip install python-dotenv>=1.0.0` |
+
+Included when installing optional dependencies: `pip3 install -r requirements-optional.txt`
+
+## Parameters
+
+| Parameter | Type | Required | Description |
+| --- | --- | --- | --- |
+| `action` | string | Yes | Operation type: `get`, `set`, `list`, `delete` |
+| `key` | string | No | Environment variable name |
+| `value` | string | No | Environment variable value (only for `set`) |
+
+## Usage
+
+Tell the Agent what key you need to configure, and it will automatically invoke this tool:
+
+- "Configure my BOCHA_API_KEY"
+- "Set OPENAI_API_KEY to sk-xxx"
+- "Show configured environment variables"
+
+Configured keys are automatically injected into the `bash` tool's execution environment.
+
+<Frame>
+  <img src="https://cdn.link-ai.tech/doc/20260202234939.png" width="800" />
+</Frame>