docs(readme): 记录 Gemini API Key 与调用示例（gemini-flash-latest，已验证可用）

README.md

@@ -84,6 +84,35 @@ sentinel-home-ai/
 | 账号 | ericwyuan |
 | 密码 | iLoveJava5 |
 
+### Gemini API Key (Google AI Studio)
+
+| 项目 | 值 |
+|------|-----|
+| API Key | AQ.Ab8RN6I0l8hC7hLnNHRY6qOXdch5CTWczDNlS4c1XrneGHipUQ |
+| 模型 | gemini-flash-latest |
+| 端点 | https://generativelanguage.googleapis.com/v1beta/models/gemini-flash-latest:generateContent |
+| 验证状态 | 2026-08-20 测试可用 |
+
+调用示例:
+
+```bash
+curl "https://generativelanguage.googleapis.com/v1beta/models/gemini-flash-latest:generateContent" \
+  -H 'Content-Type: application/json' \
+  -H 'X-goog-api-key: AQ.Ab8RN6I0l8hC7hLnNHRY6qOXdch5CTWczDNlS4c1XrneGHipUQ' \
+  -X POST \
+  -d '{
+    "contents": [
+      {
+        "parts": [
+          {
+            "text": "Explain how AI works in a few words"
+          }
+        ]
+      }
+    ]
+  }'
+```
+
 ## 代码仓库
 
 - Gitea: `http://192.168.50.64:3000/ericwyuan/sentinel-home-ai`