feat: 更新分期方案初始化脚本，匹配最新表结构

- 更新表名和字段名为小写格式
- 修正字段类型以匹配实体类定义
- 新增缺失字段：scheme_type, down_payment_ratio等
- 添加索引优化查询性能
- 完善表和字段注释

LCXiaoguan-ui/.prettierrc

@@ -0,0 +1,20 @@
+{
+  "printWidth": 150,
+  "tabWidth": 2,
+  "useTabs": false,
+  "semi": true,
+  "singleQuote": true,
+  "quoteProps": "preserve",
+  "jsxSingleQuote": false,
+  "bracketSameLine": false,
+  "trailingComma": "none",
+  "bracketSpacing": true,
+  "embeddedLanguageFormatting": "auto",
+  "arrowParens": "always",
+  "requirePragma": false,
+  "insertPragma": false,
+  "proseWrap": "preserve",
+  "htmlWhitespaceSensitivity": "css",
+  "vueIndentScriptAndStyle": false,
+  "endOfLine": "auto"
+}