feat: Implement Alpha list and metrics enhancements

- Added new metrics fields: sub_universe_sharpe, robust_universe_sharpe, two_year_sharpe, prod_correlation, pnl, check_type, and neutralization to the Alpha model.
- Updated snapshot_columns function to derive new metrics and check types from platform snapshots.
- Enhanced API to include failed checks and check types in responses.
- Created migration script to backfill existing Alpha records with new metrics and check types.
- Updated frontend components to display new metrics and allow editing of custom tags.
- Improved filtering and sorting capabilities for new metrics in the Alpha list.
- Added tests for new functionality including checks classification and metrics filtering.

frontend/src/components/AlphaDetail.tsx

@@ -384,7 +384,7 @@ export function AlphaDetail({
                   />
                 </label>
                 <label>
-                  标签
+                  自定义标签
                   <Input
                     aria-label="研究标签"
                     value={tagText}
@@ -392,7 +392,7 @@ export function AlphaDetail({
                       dirty.current = true;
                       setTagText(value);
                     }}
-                    placeholder="以逗号分隔，例如 低换手, 分析师预期"
+                    placeholder="以逗号分隔，例如 PPAC, 待活动提交"
                   />
                 </label>
                 <label>