feat(fc2b): suggestions store + modal panel components

Store: load per-image suggestions, accept (creates the tag first for
raw/creates_new_tag suggestions, then accepts by id), aliasAccept,
dismiss (client-side hide for raw tags), success toasts folded in.
Panel: people/sources groups always open, General collapsed by default;
alias picker dialog wired; shimmer skeleton while loading. SuggestionItem
shows score %, +new badge for raw tags, kebab menu. AliasPickerDialog
referenced (lands in Task 15).

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

frontend/src/components/modal/SuggestionsCategoryGroup.vue

@@ -0,0 +1,55 @@
+<template>
+  <div class="fc-sgroup">
+    <button
+      v-if="collapsible"
+      class="fc-sgroup__header fc-sgroup__header--btn"
+      @click="open = !open"
+    >
+      <v-icon size="small">{{ open ? 'mdi-chevron-down' : 'mdi-chevron-right' }}</v-icon>
+      {{ label }} ({{ items.length }})
+    </button>
+    <div v-else class="fc-sgroup__header">{{ label }}</div>
+
+    <div v-show="open" class="fc-sgroup__items">
+      <SuggestionItem
+        v-for="(s, i) in items" :key="`${s.display_name}-${i}`"
+        :suggestion="s"
+        @accept="$emit('accept', $event)"
+        @alias="$emit('alias', $event)"
+        @dismiss="$emit('dismiss', $event)"
+      />
+    </div>
+  </div>
+</template>
+
+<script setup>
+import { ref } from 'vue'
+import SuggestionItem from './SuggestionItem.vue'
+
+const props = defineProps({
+  label: { type: String, required: true },
+  items: { type: Array, required: true },
+  collapsible: { type: Boolean, default: false },
+  defaultOpen: { type: Boolean, default: true }
+})
+defineEmits(['accept', 'alias', 'dismiss'])
+
+const open = ref(props.collapsible ? props.defaultOpen : true)
+</script>
+
+<style scoped>
+.fc-sgroup { margin-bottom: 10px; }
+.fc-sgroup__header {
+  font-family: 'Inter', sans-serif;
+  font-size: 11px; font-weight: 600;
+  text-transform: uppercase; letter-spacing: 0.06em;
+  color: rgb(var(--v-theme-on-surface-variant, var(--v-theme-on-surface)));
+  margin-bottom: 4px;
+}
+.fc-sgroup__header--btn {
+  display: flex; align-items: center; gap: 4px;
+  background: none; border: none; cursor: pointer;
+  padding: 0; width: 100%; text-align: left;
+  font: inherit; text-transform: uppercase; letter-spacing: 0.06em;
+}
+</style>