refactor(frontend): simplify booking forms and convert to modals

- Simplify BookingForm: remove recurring bookings, templates, and attachments
- Replace datetime-local with separate date/time inputs for better UX
- Convert inline forms to modals (Admin spaces, Users, SpaceDetail)
- Unify Create and Edit booking forms with identical styling and structure
- Add Space field to Edit modal (read-only)
- Fix calendar initial load and set week start to Monday
- Translate all form labels and messages to Romanian

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

frontend/src/components/SpaceCalendar.vue

@@ -39,7 +39,7 @@
 </template>
 
 <script setup lang="ts">
-import { ref, computed } from 'vue'
+import { ref, computed, onMounted } from 'vue'
 import FullCalendar from '@fullcalendar/vue3'
 import dayGridPlugin from '@fullcalendar/daygrid'
 import timeGridPlugin from '@fullcalendar/timegrid'
@@ -251,6 +251,7 @@ const calendarOptions = computed<CalendarOptions>(() => ({
     right: 'dayGridMonth,timeGridWeek,timeGridDay'
   },
   timeZone: userTimezone.value,
+  firstDay: 1, // Start week on Monday (0=Sunday, 1=Monday)
   events: events.value,
   datesSet: handleDatesSet,
   editable: isEditable.value, // Enable drag/resize for admins
@@ -301,6 +302,12 @@ const refresh = () => {
   }
 }
 
+// Initialize calendar on mount
+onMounted(() => {
+  // Load initial bookings for current month
+  refresh()
+})
+
 defineExpose({ refresh })
 </script>