feat: add keybinding preset UI with toolbar, menu, and header teleport

Add KeybindingPresetToolbar with preset selector dropdown, save changes
button, and import option. Integrate into KeybindingPanel with teleported
search box and more-options menu in the settings dialog header row.

src/components/dialog/content/setting/keybinding/KeybindingPresetToolbar.vue

@@ -0,0 +1,112 @@
+<template>
+  <div class="flex items-center justify-between">
+    <Select v-model="selectedPreset">
+      <SelectTrigger class="w-64">
+        <SelectValue :placeholder="$t('g.keybindingPresets.default')">
+          {{ displayLabel }}
+        </SelectValue>
+      </SelectTrigger>
+      <SelectContent
+        disable-portal
+        class="max-w-64 min-w-0 **:[[role=listbox]]:gap-1"
+      >
+        <div class="max-w-60">
+          <SelectItem
+            value="default"
+            class="max-w-60 p-2 data-[state=checked]:bg-transparent"
+          >
+            {{ $t('g.keybindingPresets.default') }}
+          </SelectItem>
+          <SelectItem
+            v-for="name in presetNames"
+            :key="name"
+            :value="name"
+            class="max-w-60 p-2 data-[state=checked]:bg-transparent"
+          >
+            {{ name }}
+          </SelectItem>
+          <SelectSeparator class="max-w-60" />
+          <button
+            class="relative flex w-full max-w-60 cursor-pointer select-none items-center justify-between gap-3 rounded-sm border-none bg-transparent p-2 text-sm outline-none hover:bg-secondary-background-hover focus:bg-secondary-background-hover"
+            @click.stop="handleImportFromDropdown"
+          >
+            <span class="truncate">
+              {{ $t('g.keybindingPresets.importKeybindingPreset') }}
+            </span>
+            <i
+              class="icon-[lucide--download] shrink-0 text-base-foreground"
+              aria-hidden="true"
+            />
+          </button>
+        </div>
+      </SelectContent>
+    </Select>
+    <Button v-if="showSaveButton" size="lg" @click="handleSavePreset">
+      {{ $t('g.keybindingPresets.saveChanges') }}
+    </Button>
+  </div>
+</template>
+
+<script setup lang="ts">
+import { computed, ref, watch } from 'vue'
+import { useI18n } from 'vue-i18n'
+
+import Button from '@/components/ui/button/Button.vue'
+import Select from '@/components/ui/select/Select.vue'
+import SelectContent from '@/components/ui/select/SelectContent.vue'
+import SelectItem from '@/components/ui/select/SelectItem.vue'
+import SelectSeparator from '@/components/ui/select/SelectSeparator.vue'
+import SelectTrigger from '@/components/ui/select/SelectTrigger.vue'
+import SelectValue from '@/components/ui/select/SelectValue.vue'
+import { useKeybindingPresetService } from '@/platform/keybindings/presetService'
+import { useKeybindingStore } from '@/platform/keybindings/keybindingStore'
+
+const { presetNames, onPresetsChanged } = defineProps<{
+  presetNames: string[]
+  onPresetsChanged: () => void
+}>()
+
+const { t } = useI18n()
+const keybindingStore = useKeybindingStore()
+const presetService = useKeybindingPresetService()
+
+const selectedPreset = ref(keybindingStore.currentPresetName)
+
+const displayLabel = computed(() => {
+  const name =
+    selectedPreset.value === 'default'
+      ? t('g.keybindingPresets.default')
+      : selectedPreset.value
+  return keybindingStore.isCurrentPresetModified ? `${name} *` : name
+})
+
+watch(selectedPreset, async (newValue, oldValue) => {
+  if (newValue !== oldValue) {
+    await presetService.switchPreset(newValue)
+    selectedPreset.value = keybindingStore.currentPresetName
+    onPresetsChanged()
+  }
+})
+
+watch(
+  () => keybindingStore.currentPresetName,
+  (name) => {
+    selectedPreset.value = name
+  }
+)
+
+const showSaveButton = computed(
+  () =>
+    keybindingStore.currentPresetName !== 'default' &&
+    keybindingStore.isCurrentPresetModified
+)
+
+async function handleSavePreset() {
+  await presetService.savePreset(keybindingStore.currentPresetName)
+}
+
+async function handleImportFromDropdown() {
+  await presetService.importPreset()
+  onPresetsChanged()
+}
+</script>