fix(history): preserve multiple balance updates on the same day

apps/api/test/calculation.test.ts

@@ -46,6 +46,23 @@ test('correction recalculates later delta', () => {
   assert.equal(history(a)[1].delta, '20');
   assert.equal(totals([a], [], 'CNY', '2026-09-02').net, '110.10');
 });
+test('multiple same-day balances preserve ordering and use last value in totals', () => {
+  const a = p();
+  a.revisions = [
+    { ...rev('120.10', '2026-09-01'), sequence: 3 },
+    { ...rev('100.10', '2026-09-01'), sequence: 1 },
+    { ...rev('110.10', '2026-09-01'), sequence: 2 },
+  ];
+  assert.deepEqual(
+    history(a).map((r) => r.after),
+    ['100.1', '110.1', '120.1'],
+  );
+  assert.equal(history(a)[2].delta, '10');
+  assert.equal(totals([a], [], 'CNY', '2026-09-01').net, '120.10');
+  a.revisions[1].amount = '90.10';
+  assert.equal(history(a)[1].delta, '20');
+  assert.equal(totals([a], [], 'CNY', '2026-09-01').net, '120.10');
+});
 test('FX and actual changes separated', () => {
   const a = p('asset', 'USD');
   a.revisions = [rev('100', '2026-09-01'), rev('110', '2026-09-02')];

apps/api/test/integration.test.ts

@@ -232,6 +232,35 @@ test('real MySQL: authentication, isolation, history, backup and atomic failures
     );
     o = (await call('/overview', 'GET', undefined, a.cookie)).data;
     assert.equal(o.net, '570.10');
+    assert.equal(
+      (
+        await call(
+          '/positions/' + bank + '/revisions',
+          'POST',
+          { amount: '120.10', date: '2026-09-02' },
+          a.cookie,
+        )
+      ).status,
+      201,
+    );
+    const sameDay = (await call('/positions/' + bank, 'GET', undefined, a.cookie)).data.history;
+    assert.equal(sameDay.length, 3);
+    assert.equal(sameDay[2].after, '120.1');
+    assert.equal(sameDay[2].delta, '10');
+    assert.ok(sameDay[2].sequence > sameDay[1].sequence);
+    assert.equal(
+      (
+        await call(
+          '/positions/' + bank + '/revisions',
+          'POST',
+          { amount: '0', date: '2026-09-03', reason: 'repayment' },
+          a.cookie,
+        )
+      ).status,
+      400,
+    );
+    o = (await call('/overview', 'GET', undefined, a.cookie)).data;
+    assert.equal(o.net, '580.10');
     const backup = (await call('/backup', 'GET', undefined, a.cookie)).data;
     assert.equal(backup.positions.length, 4);
     assert.equal(backup.links.length, 2);
@@ -270,6 +299,13 @@ test('real MySQL: authentication, isolation, history, backup and atomic failures
       ),
     );
     assert.equal(restored.find((p: { kind: string }) => p.kind === 'debt').outgoing.length, 2);
+    const restoredHistory = restored.find(
+      (p: { kind: string; side: string }) => p.kind === 'account' && p.side === 'asset',
+    ).history;
+    assert.deepEqual(
+      restoredHistory.map((h: { after: string }) => h.after),
+      sameDay.map((h: { after: string }) => h.after),
+    );
     assert.equal(
       (await call('/backup/import', 'POST', { confirmed: true, backup }, b.cookie)).status,
       409,