refactor: improve code formatting and readability in group duty pin command and tests

- Enhanced the `pin_duty_cmd` function by improving code formatting for better readability, ensuring consistent style across the codebase.
- Updated unit tests for `pin_duty_cmd` to follow the same formatting improvements, enhancing clarity and maintainability.
- No functional changes were made; the focus was solely on code style and organization.

webapp/js/hints.test.js

@@ -82,6 +82,33 @@ describe("getDutyMarkerRows", () => {
     expect(rows[0].timePrefix).toContain("06:00");
   });
 
+  it("second duty continuation from previous day shows only end time (to HH:MM)", () => {
+    const hintDay = "2025-02-23";
+    const duties = [
+      {
+        full_name: "A",
+        start_at: "2025-02-23T00:00:00",
+        end_at: "2025-02-23T09:00:00",
+      },
+      {
+        full_name: "B",
+        start_at: "2025-02-22T09:00:00",
+        end_at: "2025-02-23T09:00:00",
+      },
+    ];
+    const rows = getDutyMarkerRows(duties, hintDay, SEP, FROM, TO);
+    expect(rows).toHaveLength(2);
+    expect(rows[0].fullName).toBe("A");
+    expect(rows[0].timePrefix).toContain(FROM);
+    expect(rows[0].timePrefix).toContain("00:00");
+    expect(rows[0].timePrefix).toContain(TO);
+    expect(rows[0].timePrefix).toContain("09:00");
+    expect(rows[1].fullName).toBe("B");
+    expect(rows[1].timePrefix).not.toContain(FROM);
+    expect(rows[1].timePrefix).toContain(TO);
+    expect(rows[1].timePrefix).toContain("09:00");
+  });
+
   it("multiple duties in one day — correct order when input is pre-sorted", () => {
     const hintDay = "2025-02-25";
     const duties = [