444 use websocket to trigger reloads (#458)

* [#444] added refresh on sync token calendar update

* [#444] added refresh on register and tests

* [#444] extracted logic for useEffects and updates

* [#444] refactored code structure to use absolute paths

__test__/utils/CalendarRangeManager.test.ts

@@ -0,0 +1,73 @@
+import {
+  getDisplayedDate,
+  setDisplayedDateAndRange,
+  calendarRangeManager,
+  getDisplayedCalendarRange,
+} from "../../src/utils/CalendarRangeManager";
+
+describe("CalendarRangeManager", () => {
+  beforeEach(() => {
+    setDisplayedDateAndRange(new Date());
+  });
+
+  it("should return a singleton instance", () => {
+    const instance1 = calendarRangeManager;
+    const instance2 = calendarRangeManager;
+
+    expect(instance1).toStrictEqual(instance2);
+  });
+
+  it("should compute and return calendar range when date is set", () => {
+    const testDate = new Date("2025-06-15T10:00:00Z");
+    setDisplayedDateAndRange(testDate);
+
+    const range = getDisplayedCalendarRange();
+    expect(range.start).toBeInstanceOf(Date);
+    expect(range.end).toBeInstanceOf(Date);
+    expect(range.start.getTime()).toBeLessThanOrEqual(testDate.getTime());
+    expect(range.end.getTime()).toBeGreaterThanOrEqual(testDate.getTime());
+  });
+
+  it("should get the default date", () => {
+    const date = getDisplayedDate();
+    expect(date).toBeInstanceOf(Date);
+  });
+
+  it("should set and get a date", () => {
+    const testDate = new Date("2025-01-15T10:00:00Z");
+    setDisplayedDateAndRange(testDate);
+
+    const retrievedDate = getDisplayedDate();
+    expect(retrievedDate).toStrictEqual(testDate);
+  });
+
+  it("should persist date across multiple calls", () => {
+    const testDate = new Date("2025-06-20T15:30:00Z");
+    setDisplayedDateAndRange(testDate);
+
+    const date1 = getDisplayedDate();
+    const date2 = getDisplayedDate();
+
+    expect(date1).toStrictEqual(date2);
+    expect(date1).toStrictEqual(testDate);
+  });
+
+  it("should update date when set multiple times", () => {
+    const date1 = new Date("2025-01-01T00:00:00Z");
+    const date2 = new Date("2025-12-31T23:59:59Z");
+
+    setDisplayedDateAndRange(date1);
+    expect(getDisplayedDate()).toStrictEqual(date1);
+
+    setDisplayedDateAndRange(date2);
+    expect(getDisplayedDate()).toStrictEqual(date2);
+  });
+
+  it("should maintain shared state (singleton behavior)", () => {
+    const testDate = new Date("2025-03-01");
+    setDisplayedDateAndRange(testDate);
+
+    // Verify CalendarRangeManager reflects the same state
+    expect(calendarRangeManager.getDate()).toStrictEqual(testDate);
+  });
+});