fix(report): 修正 approval_records.status 大小寫不一致

DB 以 SQLEnum 儲存 enum name（EXECUTION_FAILED 大寫），
而非 enum value（execution_failed 小寫）。
SQL 加 UPPER(status::text) 確保不論大小寫皆能命中。

驗證：live DB 查詢 success=0, failed=2（之前永遠 0/0）

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

apps/api/src/services/report_generation_service.py

@@ -233,8 +233,8 @@ class ReportGenerationService:
             row = await db.execute(
                 text("""
                     SELECT
-                        COUNT(*) FILTER (WHERE status = 'execution_success') AS success,
-                        COUNT(*) FILTER (WHERE status = 'execution_failed')  AS failed
+                        COUNT(*) FILTER (WHERE UPPER(status::text) = 'EXECUTION_SUCCESS') AS success,
+                        COUNT(*) FILTER (WHERE UPPER(status::text) = 'EXECUTION_FAILED')  AS failed
                     FROM approval_records
                     WHERE created_at >= :since
                 """),