fix: matplotlib DejaVu Sans 缺少 CJK glyph，配置 Microsoft YaHei + 抑制 warning

Author: jinyiwei2012

ui/mpl_imports.py

@@ -6,6 +6,20 @@
     import matplotlib
 
     matplotlib.use("TkAgg", force=True)
+
+    # 配置中文字体（防止 DejaVu Sans 缺少 CJK glyph 警告）
+    import platform
+
+    if platform.system() == "Windows":
+        matplotlib.rcParams["font.sans-serif"] = ["Microsoft YaHei", "SimHei", "DejaVu Sans"]
+    else:
+        matplotlib.rcParams["font.sans-serif"] = ["WenQuanYi Micro Hei", "Noto Sans CJK SC", "DejaVu Sans"]
+    matplotlib.rcParams["axes.unicode_minus"] = False
+
+    # 抑制缺少 glyph 的 UserWarning（CJK 字体回退时 still noisy）
+    import warnings
+    warnings.filterwarnings("ignore", message="Glyph.*missing from font.*")
+
     from matplotlib.backends.backend_tkagg import FigureCanvasTkAgg
     from matplotlib.figure import Figure