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/dropdown-menu/DropdownMenuItem.vue

@@ -0,0 +1,31 @@
+<script setup lang="ts">
+import type { DropdownMenuItemProps } from 'reka-ui'
+import type { HTMLAttributes } from 'vue'
+import { reactiveOmit } from '@vueuse/core'
+import { DropdownMenuItem, useForwardProps } from 'reka-ui'
+import { cn } from '@/lib/utils'
+
+const props = withDefaults(defineProps<DropdownMenuItemProps & {
+  class?: HTMLAttributes['class']
+  inset?: boolean
+  variant?: 'default' | 'destructive'
+}>(), {
+  variant: 'default',
+})
+
+const delegatedProps = reactiveOmit(props, 'inset', 'variant', 'class')
+
+const forwardedProps = useForwardProps(delegatedProps)
+</script>
+
+<template>
+  <DropdownMenuItem
+    data-slot="dropdown-menu-item"
+    :data-inset="inset ? '' : undefined"
+    :data-variant="variant"
+    v-bind="forwardedProps"
+    :class="cn('focus:bg-accent focus:text-accent-foreground data-[variant=destructive]:text-destructive data-[variant=destructive]:focus:bg-destructive/10 dark:data-[variant=destructive]:focus:bg-destructive/20 data-[variant=destructive]:focus:text-destructive data-[variant=destructive]:*:[svg]:text-destructive not-data-[variant=destructive]:focus:**:text-accent-foreground gap-1.5 rounded-md px-1.5 py-1 text-sm data-inset:pl-7 [&_svg:not([class*=size-])]:size-4 group/dropdown-menu-item relative flex cursor-default items-center outline-hidden select-none data-disabled:pointer-events-none data-disabled:opacity-50 [&_svg]:pointer-events-none [&_svg]:shrink-0', props.class)"
+  >
+    <slot />
+  </DropdownMenuItem>
+</template>