feat: add multi-tenant system with properties, organizations, and public booking

Implement complete multi-property architecture:
- Properties (groups of spaces) with public/private visibility
- Property managers (many-to-many) with role-based permissions
- Organizations with member management
- Anonymous/guest booking support via public API (/api/public/*)
- Property-scoped spaces, bookings, and settings
- Frontend: property selector, organization management, public booking views
- Migration script and updated seed data

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/src/views/Admin.vue

@@ -2,7 +2,12 @@
   <div class="admin">
     <Breadcrumb :items="breadcrumbItems" />
     <div class="page-header">
-      <h2>Space Management</h2>
+      <div>
+        <h2>Space Management</h2>
+        <p v-if="authStore.isManager && propertyStore.currentProperty" class="property-context">
+          Property: <strong>{{ propertyStore.currentProperty.name }}</strong>
+        </p>
+      </div>
       <button class="btn btn-primary" @click="openCreateModal">
         <Plus :size="16" />
         New Space
@@ -73,6 +78,10 @@
             <UsersIcon :size="14" />
             {{ space.capacity }}
           </span>
+          <span v-if="space.property_name" class="meta-badge meta-property" :title="'Property: ' + space.property_name">
+            <Landmark :size="11" />
+            {{ space.property_name }}
+          </span>
         </div>
         <p v-if="space.description" class="space-card-desc">{{ space.description }}</p>
       </div>
@@ -94,6 +103,15 @@
             />
           </div>
 
+          <div class="form-group">
+            <label for="property">Property *</label>
+            <select id="property" v-model.number="formData.property_id" required>
+              <option v-for="prop in availableProperties" :key="prop.id" :value="prop.id">
+                {{ prop.name }}
+              </option>
+            </select>
+          </div>
+
           <div class="form-group">
             <label for="type">Type *</label>
             <select id="type" v-model="formData.type" required>
@@ -201,10 +219,15 @@
 
 <script setup lang="ts">
 import { ref, computed, onMounted } from 'vue'
-import { spacesApi, handleApiError } from '@/services/api'
+import { spacesApi, propertiesApi, handleApiError } from '@/services/api'
+import { useAuthStore } from '@/stores/auth'
+import { usePropertyStore } from '@/stores/property'
 import Breadcrumb from '@/components/Breadcrumb.vue'
-import { Building2, Plus, Pencil, Power, Users as UsersIcon } from 'lucide-vue-next'
-import type { Space } from '@/types'
+import { Building2, Plus, Pencil, Power, Users as UsersIcon, Landmark } from 'lucide-vue-next'
+import type { Space, Property } from '@/types'
+
+const authStore = useAuthStore()
+const propertyStore = usePropertyStore()
 
 const breadcrumbItems = [
   { label: 'Dashboard', to: '/dashboard' },
@@ -212,6 +235,7 @@ const breadcrumbItems = [
 ]
 
 const spaces = ref<Space[]>([])
+const availableProperties = ref<Property[]>([])
 const loadingSpaces = ref(false)
 const activeCount = computed(() => spaces.value.filter(s => s.is_active).length)
 const inactiveCount = computed(() => spaces.value.filter(s => !s.is_active).length)
@@ -226,12 +250,23 @@ const formData = ref({
   type: 'sala',
   capacity: 1,
   description: '',
+  property_id: null as number | null,
   working_hours_start: null as number | null,
   working_hours_end: null as number | null,
   min_duration_minutes: null as number | null,
   max_duration_minutes: null as number | null
 })
 
+const loadProperties = async () => {
+  try {
+    if (authStore.isSuperadmin) {
+      availableProperties.value = await propertiesApi.listAll()
+    } else {
+      availableProperties.value = await propertiesApi.list()
+    }
+  } catch {}
+}
+
 const loadSpaces = async () => {
   loadingSpaces.value = true
   error.value = ''
@@ -274,6 +309,12 @@ const handleSubmit = async () => {
 
 const openCreateModal = () => {
   resetForm()
+  // Auto-select current property context or first available
+  if (propertyStore.currentPropertyId) {
+    formData.value.property_id = propertyStore.currentPropertyId
+  } else if (availableProperties.value.length > 0) {
+    formData.value.property_id = availableProperties.value[0].id
+  }
   showModal.value = true
 }
 
@@ -284,6 +325,7 @@ const startEdit = (space: Space) => {
     type: space.type,
     capacity: space.capacity,
     description: space.description || '',
+    property_id: space.property_id ?? null,
     working_hours_start: space.working_hours_start ?? null,
     working_hours_end: space.working_hours_end ?? null,
     min_duration_minutes: space.min_duration_minutes ?? null,
@@ -307,7 +349,8 @@ const resetForm = () => {
     working_hours_start: null,
     working_hours_end: null,
     min_duration_minutes: null,
-    max_duration_minutes: null
+    max_duration_minutes: null,
+    property_id: null
   }
 }
 
@@ -333,6 +376,7 @@ const toggleStatus = async (space: Space) => {
 
 onMounted(() => {
   loadSpaces()
+  loadProperties()
 })
 </script>
 
@@ -353,6 +397,16 @@ onMounted(() => {
   color: var(--color-text-primary);
 }
 
+.property-context {
+  font-size: 14px;
+  color: var(--color-text-secondary);
+  margin: 4px 0 0;
+}
+
+.property-context strong {
+  color: var(--color-accent);
+}
+
 /* Stats Pills */
 .stats-pills {
   display: flex;
@@ -544,6 +598,14 @@ onMounted(() => {
   color: var(--color-accent);
 }
 
+.meta-property {
+  display: inline-flex;
+  align-items: center;
+  gap: 4px;
+  background: color-mix(in srgb, var(--color-warning) 12%, transparent);
+  color: var(--color-warning);
+}
+
 .meta-item {
   display: inline-flex;
   align-items: center;