fix: booking duration calculation, tip page auth, and UI polish across frontend

Ultraworked with [Sisyphus](https://github.com/code-yeongyu/oh-my-openagent)

Co-authored-by: Sisyphus <clio-agent@sisyphuslabs.ai>

frontend/src/lib/components/today/CurrentAppointment.svelte

@@ -32,6 +32,8 @@
 			service_description?: string;
 			price?: number;
 			duration_minutes?: number;
+			override_price?: number;
+			override_duration_minutes?: number;
 		}>;
 		duration_minutes: number;
 		total_amount: number;
@@ -318,7 +320,7 @@
 									<div class="text-xs text-gray-600">{service.service_description}</div>
 								{/if}
 								<div class="mt-1 flex items-center justify-between text-xs text-gray-500">
-									<span>{service.duration_minutes} mins</span>
+									<span>{service.override_duration_minutes ?? service.duration_minutes} mins</span>
 								</div>
 							</div>
 						{/each}