PR 6: Database migration validation - fresh/upgrade test complete

✅ Database Setup:
- Created PostgreSQL kartselldb with kartsell user
- SSH port forward established (localhost:5432 → 178.104.200.7:5432)

✅ DbMigrator Fixes:
- Fixed migration path discovery (AppContext.BaseDirectory fallback)
- Added empty variable dictionary to suppress DbUp preprocessing
- Fixed PostgreSQL dollar quoting conflict ($policy$ → $$)

✅ Migration Results:
- All 21 migrations executed successfully
- Schema versions journal created and tracked
- 21 scripts processed in order, no rollback needed

Status: FRESH DATABASE DEPLOYMENT SUCCESSFUL
- kartselldb fully initialized with v16 schema
- Ready for application startup

Next: Deploy application and run integration tests

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

frontend/src/features/data-quality/pages/DataQualityPage.vue.js

@@ -0,0 +1,41 @@
+import { computed } from 'vue';
+import DataGridShell from '../../../shared/ui/DataGridShell.vue';
+// Template fixture only. Production data must come from DAT-03 and pass Zod validation.
+const rows = [];
+const columns = computed(() => [
+    { field: 'source', header: 'Source' },
+    { field: 'session', header: 'Session' },
+    { field: 'status', header: 'DQ' },
+    { field: 'rowCount', header: 'Rows' },
+    { field: 'failedRows', header: 'Failed' },
+    { field: 'sourceWatermark', header: 'Watermark' },
+    { field: 'datasetId', header: 'Dataset' },
+    { field: 'completedAt', header: 'Completed' }
+]);
+const __VLS_ctx = {
+    ...{},
+    ...{},
+};
+let __VLS_components;
+let __VLS_intrinsics;
+let __VLS_directives;
+__VLS_asFunctionalElement1(__VLS_intrinsics.main, __VLS_intrinsics.main)({});
+__VLS_asFunctionalElement1(__VLS_intrinsics.header, __VLS_intrinsics.header)({});
+__VLS_asFunctionalElement1(__VLS_intrinsics.h1, __VLS_intrinsics.h1)({});
+__VLS_asFunctionalElement1(__VLS_intrinsics.p, __VLS_intrinsics.p)({});
+const __VLS_0 = DataGridShell;
+// @ts-ignore
+const __VLS_1 = __VLS_asFunctionalComponent1(__VLS_0, new __VLS_0({
+    rows: (__VLS_ctx.rows),
+    columns: (__VLS_ctx.columns),
+    emptyMessage: "DAT-03 계약이 구현되면 서버 검증 결과가 표시됩니다.",
+}));
+const __VLS_2 = __VLS_1({
+    rows: (__VLS_ctx.rows),
+    columns: (__VLS_ctx.columns),
+    emptyMessage: "DAT-03 계약이 구현되면 서버 검증 결과가 표시됩니다.",
+}, ...__VLS_functionalComponentArgsRest(__VLS_1));
+// @ts-ignore
+[rows, columns,];
+const __VLS_export = (await import('vue')).defineComponent({});
+export default {};