fix(investments): align roles and date contracts

Identify income dependencies by role and document screen-specific dates.
Convert inclusive calendar days into half-open source ranges while
preserving operation timestamps and existing stored coverage.

test/upcoming-events.e2e-spec.ts

@@ -497,4 +497,38 @@ describe('saved payout calendars and complete forecasts (SQLite HTTP)', () => {
     await get(`brokerage-accounts/account/events?${query}`).expect(400);
     expect(upstream.getDividends).not.toHaveBeenCalled();
   });
+
+  it('uses UTC today for an end-only range and includes the entire leap day', async () => {
+    const today = new Date().toISOString().slice(0, 10);
+    await get('brokerage-accounts/account/events?to=2096-02-29').expect(200);
+    await settled();
+    expect(upstream.getDividends).toHaveBeenCalledWith(
+      'synthetic-owner',
+      shareUid,
+      today,
+      '2096-02-29',
+    );
+    upstream.getDividends.mockResolvedValue([
+      {
+        recordDate: {
+          seconds: String(Date.parse('2096-02-29T23:59:59Z') / 1000),
+        },
+        dividendNet: { units: '7', currency: 'rub' },
+      },
+      {
+        recordDate: time('2096-03-01'),
+        dividendNet: { units: '99', currency: 'rub' },
+      },
+    ]);
+    const range = { from: '2096-02-29', to: '2096-02-29' };
+    await events(false, 'account', 'owner', range).expect(200);
+    await settled();
+    const result = (await events(true, 'account', 'owner', range).expect(200))
+      .body as UpcomingEventsResourceDto;
+    expect(result.data?.events).toHaveLength(1);
+    expect(result.data?.events[0]).toMatchObject({
+      date: '2096-02-29',
+      projectedAmount: { currency: 'RUB', value: '14' },
+    });
+  });
 });