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/tests/schema.spec.js

@@ -0,0 +1,22 @@
+import { describe, expect, it } from 'vitest';
+import { dataQualityRunSchema } from '../schema';
+const valid = {
+    runId: '00000000-0000-0000-0000-000000000001',
+    source: 'KRX',
+    session: '2026-08-01',
+    status: 'PASS',
+    rowCount: 100,
+    failedRows: 0,
+    sourceWatermark: 'KRX:2026-08-01',
+    datasetId: 'dataset-1',
+    contentHash: 'hash-1',
+    completedAt: '2026-08-01T09:00:00Z'
+};
+describe('data quality contract', () => {
+    it('accepts a valid run', () => {
+        expect(dataQualityRunSchema.safeParse(valid).success).toBe(true);
+    });
+    it('rejects failed rows greater than total rows', () => {
+        expect(dataQualityRunSchema.safeParse({ ...valid, failedRows: 101 }).success).toBe(false);
+    });
+});