feat(stage1): register primary outcome candidates

.learnings/ERRORS.md

@@ -2,6 +2,35 @@
 
 Command failures and integration errors.
 
+---
+## [ERR-20260920-030] gshs-workbook-column-name
+
+**Logged**: 2026-09-20
+**Priority**: low
+**Status**: resolved
+**Area**: docs
+
+### Summary
+An exploratory GSHS workbook filter referenced `column` instead of the actual `column_name` field.
+
+### Error
+`KeyError: 'column'`
+
+### Context
+The workbook schema was printed in the same command and showed the correct field name. The failed command was read-only and changed no data.
+
+### Suggested Fix
+Inspect the sheet columns first and filter on `column_name`.
+
+### Metadata
+- Reproducible: yes
+- Related Files: `Dataset/GSHS-全球学生健康调查数据/GSHS/02_documentation/GSHS_数据字典.xlsx`
+- Pattern-Key: runtime.python-exception
+
+### Resolution
+- **Resolved**: 2026-09-20
+- **Notes**: Re-ran the read-only extraction using `column_name` and obtained the intended candidate rows.
+
 ---
 ## [ERR-20260920-028] python-assignment-expression-comprehension