Add multiple network maps, graph UX improvements, and full backup import.

Support per-map contact membership with scoped graph views, relation editing on edges, layout caching, and automatic detection of full JSON backups so contacts and relations import together.

Co-authored-by: Cursor <cursoragent@cursor.com>

frontend/src/components/NetworkMapSwitcher.vue

@@ -0,0 +1,56 @@
+<template>
+  <div class="map-switcher">
+    <label class="map-switcher-label">Карта</label>
+    <select
+      class="form-control map-switcher-select"
+      :value="modelValue"
+      @change="onSelect"
+    >
+      <option v-for="map in maps" :key="map.id" :value="String(map.id)">
+        {{ map.name }}
+      </option>
+    </select>
+    <button type="button" class="btn btn-secondary btn-sm" @click="$emit('create')">
+      + Новая
+    </button>
+    <button
+      v-if="modelValue"
+      type="button"
+      class="btn btn-secondary btn-sm"
+      title="Настройки карты"
+      @click="$emit('manage', modelValue)"
+    >
+      ⚙
+    </button>
+  </div>
+</template>
+
+<script setup>
+defineProps({
+  maps: { type: Array, default: () => [] },
+  modelValue: { type: String, default: '' },
+})
+const emit = defineEmits(['update:modelValue', 'create', 'manage'])
+
+function onSelect(event) {
+  emit('update:modelValue', event.target.value)
+}
+</script>
+
+<style scoped>
+.map-switcher {
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  flex-wrap: wrap;
+}
+.map-switcher-label {
+  font-size: 12px;
+  color: var(--text-muted);
+  white-space: nowrap;
+}
+.map-switcher-select {
+  min-width: 160px;
+  max-width: 240px;
+}
+</style>