refactor(dateTime): streamline slot handling and improve session management

lib/appointmentSlots.js

@@ -1,19 +1,17 @@
-const MORNING_END = "12:00";
-
 export function adaptSlots(slotsResponse) {
   const sessions = slotsResponse?.data?.sessions ?? slotsResponse?.sessions ?? [];
 
-  const morning = [];
-  const evening = [];
-
-  sessions.forEach((session) => {
-    (session.slots ?? []).forEach((slot) => {
-      const target = slot.start_time < MORNING_END ? morning : evening;
-      target.push(slot);
-    });
-  });
-
-  return { morning, evening };
+  // Group slots by the shifts the backend already returns; the front does not
+  // decide shift boundaries (no hard-coded morning/evening split). Each session
+  // becomes one tab labelled with its own time range.
+  return sessions
+    .filter((session) => Array.isArray(session.slots) && session.slots.length > 0)
+    .map((session) => ({
+      start_time: session.start_time,
+      end_time: session.end_time,
+      label: `${session.start_time} - ${session.end_time}`,
+      slots: session.slots,
+    }));
 }
 
 export function hasAvailable(slots) {