Migración a shadcn-vue + Tailwind CSS v4

- Tailwind CSS v4 con @tailwindcss/vite
- shadcn-vue: 19 componentes UI (button, card, dialog, table, select,
  tabs, sidebar, separator, breadcrumb, badge, avatar, dropdown-menu,
  tooltip, input, switch, sheet, skeleton)
- Sidebar collapsible con íconos Lucide
- Theme Teloprax en CSS variables (rojo #E63946, negro #1A1A2E)
- LoginView, DashboardView, CalendarView, SchedulerView migrados
- Eliminado AppShell.vue manual (reemplazado por SidebarProvider)
- Layout con breadcrumb, sidebar trigger, header unificado

src/components/ui/avatar/Avatar.vue

@@ -0,0 +1,22 @@
+<script setup lang="ts">
+import type { HTMLAttributes } from 'vue'
+import type { AvatarVariants } from '.'
+import { AvatarRoot } from 'reka-ui'
+import { cn } from '@/lib/utils'
+import { avatarVariants } from '.'
+
+const props = defineProps<{
+  class?: HTMLAttributes['class']
+  size?: AvatarVariants['size']
+}>()
+</script>
+
+<template>
+  <AvatarRoot
+    data-slot="avatar"
+    :data-size="size ?? 'default'"
+    :class="cn(avatarVariants({ size }), props.class)"
+  >
+    <slot />
+  </AvatarRoot>
+</template>