feat: 引入 ECharts 统一图表并完善员工画像标签分页

后端优化员工行为画像服务和辅助函数，完善系统设置模型和
配置持久化，前端引入 ECharts 替换所有图表组件实现统一
渲染，新增员工画像标签分页器和数字员工工作记录组件，优
化工作台响应式布局和登录页过渡动画，完善预算中心和数字
员工页面样式细节。

server/src/app/schemas/settings.py

@@ -21,6 +21,17 @@ class SettingsCompanyForm(BaseModel):
         return value.strip()
 
 
+class SettingsAppearanceForm(BaseModel):
+    themeSkin: str = Field(default="sky", max_length=64)
+
+    @field_validator("themeSkin", mode="before")
+    @classmethod
+    def strip_string(cls, value: str | None) -> str | None:
+        if value is None:
+            return None
+        return value.strip()
+
+
 class SettingsAdminForm(BaseModel):
     adminAccount: str = Field(min_length=1, max_length=120)
     adminEmail: str = Field(default="", max_length=255)
@@ -162,6 +173,7 @@ class SettingsMailForm(BaseModel):
 
 class SettingsRead(BaseModel):
     companyForm: SettingsCompanyForm
+    appearanceForm: SettingsAppearanceForm = Field(default_factory=SettingsAppearanceForm)
     adminForm: SettingsAdminForm
     sessionForm: SettingsSessionForm
     hermesForm: dict
@@ -173,6 +185,7 @@ class SettingsRead(BaseModel):
 
 class SettingsWrite(BaseModel):
     companyForm: SettingsCompanyForm
+    appearanceForm: SettingsAppearanceForm = Field(default_factory=SettingsAppearanceForm)
     adminForm: SettingsAdminForm
     sessionForm: SettingsSessionForm
     hermesForm: dict