chore: 著作権とライセンスについての情報を各ファイルに追加する (#11348)

* chore: Add the SPDX information to each file

Add copyright and licensing information as defined in version 3.0 of
the REUSE Specification.

* tweak format

---------

Co-authored-by: syuilo <Syuilotan@yahoo.co.jp>

packages/frontend/src/ui/_common_/stream-indicator.vue

@@ -1,3 +1,8 @@
+<!--
+SPDX-FileCopyrightText: syuilo and other misskey contributors
+SPDX-License-Identifier: AGPL-3.0-only
+-->
+
 <template>
 <div v-if="hasDisconnected && defaultStore.state.serverDisconnectedBehavior === 'quiet'" :class="$style.root" class="_panel _shadow" @click="resetDisconnected">
 	<div><i class="ti ti-alert-triangle"></i> {{ i18n.ts.disconnectedFromServer }}</div>