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/DropdownMenuCheckboxItem.vue

@@ -0,0 +1,43 @@
+<script setup lang="ts">
+import type { DropdownMenuCheckboxItemEmits, DropdownMenuCheckboxItemProps } from 'reka-ui'
+
+import type { HTMLAttributes } from 'vue'
+import { CheckIcon } from '@lucide/vue'
+import { reactiveOmit } from '@vueuse/core'
+import {
+  DropdownMenuCheckboxItem,
+  DropdownMenuItemIndicator,
+  useForwardPropsEmits,
+} from 'reka-ui'
+import { cn } from '@/lib/utils'
+
+const props = defineProps<DropdownMenuCheckboxItemProps & { class?: HTMLAttributes['class'] }>()
+const emits = defineEmits<DropdownMenuCheckboxItemEmits>()
+
+const delegatedProps = reactiveOmit(props, 'class')
+
+const forwarded = useForwardPropsEmits(delegatedProps, emits)
+</script>
+
+<template>
+  <DropdownMenuCheckboxItem
+    data-slot="dropdown-menu-checkbox-item"
+    v-bind="forwarded"
+    :class="cn(
+      'focus:bg-accent focus:text-accent-foreground focus:**:text-accent-foreground gap-1.5 rounded-md py-1 pr-8 pl-1.5 text-sm data-inset:pl-7 [&_svg:not([class*=size-])]:size-4 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,
+    )"
+  >
+    <span
+      class="absolute right-2 flex items-center justify-center pointer-events-none"
+      data-slot="dropdown-menu-checkbox-item-indicator"
+    >
+      <DropdownMenuItemIndicator>
+        <slot name="indicator-icon">
+          <CheckIcon />
+        </slot>
+      </DropdownMenuItemIndicator>
+    </span>
+    <slot />
+  </DropdownMenuCheckboxItem>
+</template>