feat(前端界面): 统一右侧栏按需显示规则

assets/webui/index.html

@@ -801,7 +801,7 @@
 				</div>
 			</section>
 
-			<aside class="meta-panel">
+			<aside class="meta-panel" data-empty="true">
 				<div id="metaTabs" class="navigation-tabs">
 					<button id="documentMetaTab" type="button" data-selected="true">文档</button>
 					<button id="fontsMetaTab" type="button" data-selected="false" tabindex="-1">字体</button>
@@ -911,7 +911,7 @@
 						</section>
 					</div>
 					<div id="metaFontsPanel" hidden>
-						<section class="doc-font-panel">
+						<section id="docFontPanel" class="doc-font-panel" hidden>
 							<div class="panel-row">
 								<div id="docFontPanelTitle" class="panel-title compact">文档字体</div>
 								<span id="docFontSummary" class="count-pill">0</span>