Display all block times in AM/PM format instead of 24-hour

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

frontend/src/components/ScheduleBlock.vue

@@ -14,7 +14,7 @@
         <span v-if="subjectName && block.label" class="block-label-suffix"> - {{ block.label }}</span>
       </div>
       <div class="block-time">
-        {{ block.time_start }} – {{ block.time_end }}
+        {{ formatTime(block.time_start) }} – {{ formatTime(block.time_end) }}
         <span class="block-duration" :class="{ 'block-duration-custom': block.duration_minutes != null }">
           · {{ durationLabel }}
         </span>
@@ -35,6 +35,14 @@ const props = defineProps({
   compact: { type: Boolean, default: false },
 })
 
+function formatTime(str) {
+  if (!str) return ''
+  const [h, m] = str.split(':').map(Number)
+  const period = h >= 12 ? 'PM' : 'AM'
+  const hour = h % 12 || 12
+  return `${hour}:${String(m).padStart(2, '0')} ${period}`
+}
+
 const subjectColor = computed(() => props.block.subject?.color || '#475569')
 const subjectName = computed(() => props.block.subject?.name || null)