feat(api): add REST controllers, services, entities and 15-min timeline grid

src/main/java/com/caspos/dto/CreateReservationRequest.java

@@ -0,0 +1,18 @@
+package com.caspos.dto;
+
+import java.time.OffsetDateTime;
+import java.util.List;
+import java.util.UUID;
+
+public record CreateReservationRequest(
+    String firstName,
+    String lastName,
+    String phone,
+    String email,
+    List<UUID> tableIds,
+    OffsetDateTime startTime,
+    OffsetDateTime endTime,
+    int guestCount,
+    String specialRequests,
+    List<String> tags
+) {}