feat(转换能力): 支持原生与网页批量并行

assets/webui/index.html

@@ -199,6 +199,7 @@
 						<div id="convertFontRow" class="form-row" hidden><label for="convertFontMode">字体</label><select id="convertFontMode"><option value="0">保持</option><option value="1">内嵌</option><option value="2">外部</option></select></div>
 						<div id="convertDPIRow" class="form-row" hidden><label for="convertDPI">精度</label><select id="convertDPI"><option value="96">96 dpi</option><option value="150">150 dpi</option><option value="300" selected>300 dpi</option><option value="600">600 dpi</option></select></div>
 						<div class="form-row"><label for="convertDestination">保存</label><select id="convertDestination"><option value="directory">目录</option><option value="archive">打包</option></select></div>
+						<div class="form-row"><label for="convertParallel">并行</label><input id="convertParallel" type="number" min="1" step="1" placeholder="自动"></div>
 					</div>
 					<button id="convertClose" class="button" type="button">关闭</button><button id="convertCancel" class="button" type="button" hidden>取消</button><button id="convertStart" class="button" type="submit" disabled>转换</button>
 				</div>