fix: harden store writes, strict schemas, null cfg

test/unit/format.test.ts

@@ -74,6 +74,17 @@ describe('formatDbError', () => {
         )
     })
 
+    it('joins detail and hint', () => {
+        const error = Object.assign(new Error('boom'), {
+            code: '23505',
+            detail: 'Key (id)=(1) already exists.',
+            hint: 'use upsert'
+        })
+        expect(formatDbError('postgres', error)).toBe(
+            '[postgres 23505] boom (Key (id)=(1) already exists. | use upsert)'
+        )
+    })
+
     it('handles non-Error values', () => {
         expect(formatDbError('mysql', 'boom')).toBe('[mysql] boom')
     })