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/InteractionIntensitySelect.vue

@@ -0,0 +1,26 @@
+<template>
+  <select
+    class="form-control"
+    :value="modelValue"
+    @change="onChange"
+  >
+    <option v-for="opt in options" :key="opt.value" :value="opt.value">
+      {{ opt.label }}
+    </option>
+  </select>
+</template>
+
+<script setup>
+import { INTERACTION_INTENSITIES } from '../domain/networkChoices'
+
+defineProps({
+  modelValue: { type: String, default: 'intense' },
+  options: { type: Array, default: () => INTERACTION_INTENSITIES },
+})
+
+const emit = defineEmits(['update:modelValue'])
+
+function onChange(e) {
+  emit('update:modelValue', e.target.value)
+}
+</script>