feat: Enhance session handling in timetable and UI

- Introduced session types (exams, credits, consultations, coursework defenses) with distinct icons and colors for better visibility in the UI.
- Updated PlansScreen, ScheduleScreen, and WeekGrid to display session information appropriately.
- Modified CalendarView and PlansView to include session indicators in the calendar and plans.
- Enhanced LessonCard and CompactLesson to show session details and adjust styling based on session presence.
- Added new SessionMark component for consistent session representation across Android and iOS.
- Updated server logic to handle session entries from external documents, ensuring accurate timetable representation.
- Improved date parsing to accommodate session-related dates in various formats.
- Added tests to verify session handling and date parsing functionality.

test/weeks.test.js

@@ -121,3 +121,18 @@ test("Парсер: 23-БА получает номера недель и дат
       for (const n of [a, b ?? a])
         assert.equal(n % 2, l.variant === "upper" ? 1 : 0, l.raw);
 });
+
+test("Даты числами: «10.09;15.10;19.11;17.12», но не время пары", () => {
+  // ИСФ пишет дни информирования списком дат, как в 23-АРХ.
+  assert.deepEqual(parseTextDates("Единый день информирования 10.09;15.10;19.11;17.12", 2026), [
+    "2026-09-10",
+    "2026-10-15",
+    "2026-11-19",
+    "2026-12-17",
+  ]);
+  assert.deepEqual(parseTextDates("03.10, 17.10. Физика", 2026), ["2026-10-03", "2026-10-17"]);
+  assert.deepEqual(parseTextDates("12.01.2027; 19.01.2027 Экзамен", 2026), ["2027-01-12", "2027-01-19"]);
+  // One number pair alone or a time range is a time, not a date.
+  for (const time of ["10.05 Лекция", "10.05-11.30", "16.50 Информационный час", "09.11 по 06.12 практика"])
+    assert.deepEqual(parseTextDates(time, 2026), [], time);
+});