docs: add Zhipu GLM coding plan configuration

Refactor to use protocol-based model_list configuration instead of adding
Anthropic-style API support. Zhipu GLM coding plan can use the
existing zhipu/ protocol with a custom api_base.

Changes:
- Add glm-4.7 model config to config.example.json
- Document Zhipu GLM coding plan endpoint configuration in README
- Add Chinese documentation for Zhipu GLM coding plan in README.zh.md

The new architecture (PR #492) supports zero-code provider addition
through protocol-based model_list configuration.

Addressing reviewer feedback:
- Use new protocol-based provider way from PR #492
- Zhipu GLM coding plan can use OpenAI-style (zhipu/) protocol
- No code changes needed, just configuration

README.md

@@ -877,6 +877,16 @@ This design also enables **multi-agent support** with flexible provider selectio
 }
 ```
 
+> **Zhipu GLM Coding Plan**: For the Zhipu GLM coding plan endpoint, specify a custom `api_base`:
+> ```json
+> {
+>   "model_name": "glm-4.7-coding",
+>   "model": "zhipu/glm-4.7",
+>   "api_key": "your-key",
+>   "api_base": "https://api.z.ai/api/paas/v4"
+> }
+> ```
+
 **DeepSeek**
 
 ```json

README.zh.md

@@ -512,6 +512,16 @@ Agent 读取 HEARTBEAT.md
 }
 ```
 
+> **智谱 GLM 编码计划（GLM Coding Plan）**: 如需使用智谱 GLM 编码计划端点，可指定自定义 `api_base`：
+> ```json
+> {
+>   "model_name": "glm-4.7-coding",
+>   "model": "zhipu/glm-4.7",
+>   "api_key": "your-key",
+>   "api_base": "https://api.z.ai/api/paas/v4"
+> }
+> ```
+
 **DeepSeek**
 
 ```json

config/config.example.json

@@ -43,6 +43,13 @@
       "model": "openai/gpt-5.2",
       "api_key": "sk-key2",
       "api_base": "https://api2.example.com/v1"
+    },
+    {
+      "model_name": "glm-4.7",
+      "model": "zhipu/glm-4.7",
+      "api_key": "YOUR_ZHIPU_API_KEY",
+      "api_base": "https://open.bigmodel.cn/api/paas/v4",
+      "_comment": "Zhipu GLM-4.7 model. For Zhipu GLM coding plan, use api_base: https://api.z.ai/api/paas/v4"
     }
   ],
   "channels": {