fix: 移除不再使用的 DartNode 赞助链接

feat: 更新 matplotlib 字体设置以支持中文图表

README.md

@@ -214,8 +214,6 @@ Thanks to the following projects:
 
 #### 企业
 
-[![Powered by DartNode](https://dartnode.com/branding/DN-Open-Source-sm.png)](https://dartnode.com "Powered by DartNode - Free VPS for Open Source")
-
 <div align="center">
     <a href="https://share.302.ai/UoTruU" target="_blank">
     <img src="./docs/302ai.jpg">

README_EN.md

@@ -194,8 +194,6 @@ Thanks to the following projects:
 
 ### 💖 Sponsor
 
-[![Powered by DartNode](https://dartnode.com/branding/DN-Open-Source-sm.png)](https://dartnode.com "Powered by DartNode - Free VPS for Open Source")
-
 [Buy Me a Coffee](./docs/sponser.md)
 
 Thanks to sponsors:

backend/app/core/prompts/coder.py

@@ -90,7 +90,7 @@ plt.rcParams.update({{
     'savefig.bbox': 'tight',
     'savefig.pad_inches': 0.1,
 }})
-plt.rcParams['font.sans-serif'] = ['Arial Unicode MS', 'SimHei', 'DejaVu Sans']
+plt.rcParams['font.sans-serif'] = ['Noto Sans CJK JP']
 plt.rcParams['axes.unicode_minus'] = False
 sns.set_theme(style='ticks')
 
@@ -126,6 +126,7 @@ FIG_SQUARE = (6, 6)
 - 低分辨率 PNG（用 300dpi，保存为 PNG 即可）
 
 ## 必须遵守
+- 只要用 matplotlib / seaborn 画中文图，必须先设置 `plt.rcParams['font.sans-serif'] = ['Noto Sans CJK JP']` 和 `plt.rcParams['axes.unicode_minus'] = False`
 - 去掉上右边框（已通过全局配置实现）
 - 使用统一的 COLORS 配色方案
 - 折线图用 `fill_between` 添加置信带