Walkthrough: Standardize Points Ratio

1. Goal

Standardize the Points-to-Yuan ratio to 1 Yuan = 1 Point, and remove the decimal display logic (previous 100 Points = 1 Yuan) across the system.

Core Logic (internal/pkg/points/convert.go):
- Updated CentsToPoints to (cents * rate) / 100.
- Updated PointsToCents to (points * 100) / rate.
- Added unit tests to verify 100 Cents = 1 Point.
Service Layer (internal/service/user):
- Updated points_convert.go to use points_exchange_rate config key.
- Added PointsToCents method for reverse calculation.
- Updated lottery_app.go to use PointsToCents for accurate deduction calculation.
DB Config:
- Expects points_exchange_rate (default 1) instead of points_exchange_per_cent.

System Configs:
- Added "Points Configuration" section.
- Allows setting "1 Yuan = N Points" (Default 1).

Goal: Ensure Points are displayed as integers and values are consistent.
Files Modified:
- pages-user/points/index.vue
- pages-user/orders/detail.vue
- pages-user/tasks/index.vue
- pages/shop/index.vue (Fixed / 100 division for points)
- pages-shop/shop/detail.vue (Fixed / 100 division for points)
Changes:
- Removed incorrect / 100 division for Points display while keeping it for Money (Yuan) display.
- formated points to use .toFixed(0) to remove decimal places.

Script: docs/standardize_points_ratio/migration.sql
Action Required: Run this script to shrink existing point values by 100x to match the new 1:1 definition.

Unit Tests:
- go test internal/pkg/points/... passed.
Manual Check:
- TestCentsToPoints confirmed 100 Cents -> 1 Point.
- TestRefundPointsAmount confirmed proportional refund works with integer points.