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.

src/modules/investments/income/income-period.spec.ts

@@ -53,4 +53,18 @@ describe('income period planning', () => {
       to: new Date('2026-08-27T21:44:18.510Z'),
     });
   });
+  it.each([
+    ['2024-02-29', '2024-02-28T21:00:00.000Z', '2024-02-29T21:00:00.000Z'],
+    ['2025-12-31', '2025-12-30T21:00:00.000Z', '2025-12-31T21:00:00.000Z'],
+  ])('maps inclusive %s to one full half-open Moscow day', (date, from, to) => {
+    expect(
+      dateOnlyBounds(
+        { from: date, to: date },
+        new Date('2026-01-01T12:00:00Z'),
+      ),
+    ).toEqual({
+      from: new Date(from),
+      to: new Date(to),
+    });
+  });
 });