Add event list feature (009-list-events)

Enable users to see all their saved events on the home screen, sorted
by date with upcoming events first. Key capabilities:

- EventCard with title, relative time display, and organizer/attendee
  role badge
- Sortable EventList with past-event visual distinction (faded style)
- Empty state when no events are stored
- Swipe-to-delete gesture with confirmation dialog
- Floating action button for quick event creation
- Rename router param :token → :eventToken across all views
- useRelativeTime composable (Intl.RelativeTimeFormat)
- useEventStorage: add validation, removeEvent(), reactive versioning
- Full E2E and unit test coverage for all new components

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

frontend/src/components/EventCard.vue

@@ -0,0 +1,172 @@
+<template>
+  <div
+    class="event-card"
+    :class="{ 'event-card--past': isPast, 'event-card--swiping': isSwiping }"
+    :style="swipeStyle"
+    @touchstart="onTouchStart"
+    @touchmove="onTouchMove"
+    @touchend="onTouchEnd"
+  >
+    <RouterLink :to="`/events/${eventToken}`" class="event-card__link">
+      <span class="event-card__title">{{ title }}</span>
+      <span class="event-card__time">{{ relativeTime }}</span>
+    </RouterLink>
+    <span v-if="eventRole" class="event-card__badge" :class="`event-card__badge--${eventRole}`">
+      {{ eventRole === 'organizer' ? 'Organizer' : 'Attendee' }}
+    </span>
+    <button
+      class="event-card__delete"
+      type="button"
+      :aria-label="`Remove ${title}`"
+      @click.stop="$emit('delete', eventToken)"
+    >
+      ×
+    </button>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { ref, computed } from 'vue'
+import { RouterLink } from 'vue-router'
+
+const props = defineProps<{
+  eventToken: string
+  title: string
+  relativeTime: string
+  isPast: boolean
+  eventRole?: 'organizer' | 'attendee'
+}>()
+
+const emit = defineEmits<{
+  delete: [eventToken: string]
+}>()
+
+const SWIPE_THRESHOLD = 80
+
+const startX = ref(0)
+const deltaX = ref(0)
+const isSwiping = ref(false)
+
+const swipeStyle = computed(() => {
+  if (deltaX.value === 0) return {}
+  return { transform: `translateX(${deltaX.value}px)` }
+})
+
+function onTouchStart(e: TouchEvent) {
+  const touch = e.touches[0]
+  if (!touch) return
+  startX.value = touch.clientX
+  deltaX.value = 0
+  isSwiping.value = false
+}
+
+function onTouchMove(e: TouchEvent) {
+  const touch = e.touches[0]
+  if (!touch) return
+  const diff = touch.clientX - startX.value
+  // Only allow leftward swipe
+  if (diff < 0) {
+    deltaX.value = diff
+    isSwiping.value = true
+  }
+}
+
+function onTouchEnd() {
+  if (deltaX.value < -SWIPE_THRESHOLD) {
+    emit('delete', props.eventToken)
+  }
+  deltaX.value = 0
+  isSwiping.value = false
+}
+</script>
+
+<style scoped>
+.event-card {
+  display: flex;
+  align-items: center;
+  background: var(--color-card);
+  border-radius: var(--radius-card);
+  box-shadow: var(--shadow-card);
+  padding: var(--spacing-md) var(--spacing-lg);
+  gap: var(--spacing-sm);
+}
+
+.event-card--past {
+  opacity: 0.6;
+  filter: saturate(0.5);
+}
+
+.event-card:not(.event-card--swiping) {
+  transition: opacity 0.2s ease, filter 0.2s ease, transform 0.2s ease;
+}
+
+.event-card__link {
+  flex: 1;
+  display: flex;
+  flex-direction: column;
+  gap: 0.15rem;
+  text-decoration: none;
+  color: inherit;
+  min-width: 0;
+}
+
+.event-card__title {
+  font-size: 0.95rem;
+  font-weight: 600;
+  color: var(--color-text);
+  white-space: nowrap;
+  overflow: hidden;
+  text-overflow: ellipsis;
+}
+
+.event-card__time {
+  font-size: 0.8rem;
+  font-weight: 400;
+  color: #888;
+}
+
+.event-card__badge {
+  font-size: 0.7rem;
+  font-weight: 600;
+  padding: 0.15rem 0.5rem;
+  border-radius: 999px;
+  white-space: nowrap;
+  flex-shrink: 0;
+}
+
+.event-card__badge--organizer {
+  background: var(--color-accent);
+  color: #fff;
+}
+
+.event-card__badge--attendee {
+  background: #e0e0e0;
+  color: #555;
+}
+
+.event-card__delete {
+  flex-shrink: 0;
+  width: 28px;
+  height: 28px;
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  background: none;
+  border: none;
+  font-size: 1.2rem;
+  color: #bbb;
+  cursor: pointer;
+  border-radius: 50%;
+  transition: color 0.15s ease, background 0.15s ease;
+}
+
+.event-card__delete:hover {
+  color: #d32f2f;
+  background: rgba(211, 47, 47, 0.08);
+}
+
+.event-card__delete:focus-visible {
+  outline: 2px solid var(--color-accent);
+  outline-offset: 2px;
+}
+</style>