fix: Correct UI store instantiation in form components

This commit corrects the UI store instantiation in the following form components:
- AsistenciaForm.vue
- EmpleadoForm.vue
- PlanillaForm.vue
- TareaForm.vue

The components now correctly import `useUi` from `~/stores/useUi` and instantiate the store using `const uiStore = useUi()`. This adheres to the correct Pinia conventions.

ui/src/views/asistencias/AsistenciaForm.vue

@@ -48,7 +48,7 @@
 <script setup>
 import { ref, reactive, onMounted, onUnmounted, computed, watch } from 'vue';
 import { useAsistenciasStore } from '../../stores/useAsistencias';
-import { useUiStore } from '../../stores/useUiStore'; // Import UI store
+import { useUi } from '@/stores/useUi'; // Corrected UI store import
 import { useRouter, useRoute } from 'vue-router';
 
 const props = defineProps({
@@ -58,7 +58,7 @@ const props = defineProps({
 const router = useRouter();
 const route = useRoute(); 
 const asistenciasStore = useAsistenciasStore();
-const uiStore = useUiStore(); // Instantiate UI store
+const uiStore = useUi(); // Corrected UI store instantiation
 
 const formatDateTimeForInput = (dateString) => {
   const date = dateString ? new Date(dateString) : new Date();