docs: 添加项目图标

- 添加 .asset/impress_sig_mesh_hacs.png 作为 HACS 集成图标
- 在 hacs.json 中配置 icon 字段
- 在 README.md 顶部显示图标
- 更新 .gitignore 仅保留图标文件

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.gitignore

@@ -54,6 +54,10 @@ changelog.md
 CHANGELOG.md
 .hacs/
 
+# 资产文件（仅保留 PNG 图标）
+.asset/*
+!.asset/impress_sig_mesh_hacs.png
+
 # 测试
 .pytest_cache/
 .coverage

README.md

@@ -1,5 +1,7 @@
 # SigMesh Gateway - Home Assistant 集成
 
+![logo](.asset/impress_sig_mesh_hacs.png)
+
 [![hacs_badge](https://img.shields.io/badge/HACS-Default-41BDF5.svg)](https://github.com/hacs/integration)
 [![GitHub Release](https://img.shields.io/github/release/impress-sig-mesh/sigmesh_gateway.svg)](https://github.com/impress-sig-mesh/sigmesh_gateway/releases)
 

hacs.json

@@ -5,5 +5,6 @@
   "render_readme": true,
   "zip_release": true,
   "homeassistant": "2024.1.0",
-  "hacs": "1.34.0"
+  "hacs": "1.34.0",
+  "icon": ".asset/impress_sig_mesh_hacs.png"
 }