style(mode_workflow): 渠道下拉箭头右对齐

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

examples/mode_workflow/index.html

@@ -250,8 +250,10 @@ select:focus,input:focus{border-color:var(--navy)}
 .modal .mf{display:flex;justify-content:flex-end;gap:10px;padding:0 18px 18px}
 /* 渠道下拉多选 */
 .dd{position:relative}
-.dd-btn{width:100%;text-align:left;padding:7px 10px;border:1px solid var(--line-dark);border-radius:6px;
+.dd-btn{width:100%;display:flex;justify-content:space-between;align-items:center;gap:8px;
+  text-align:left;padding:7px 10px;border:1px solid var(--line-dark);border-radius:6px;
   background:#fff;font-size:13px;color:var(--ink)}
+.dd-btn .dd-arrow{color:var(--ink-faint);flex:none}
 .dd-btn:focus{border-color:var(--navy)}
 .dd-panel{position:absolute;left:0;right:0;top:calc(100% + 4px);z-index:10;
   background:#fff;border:1px solid var(--line-dark);border-radius:8px;
@@ -781,7 +783,8 @@ function selectedPlatforms(){
 function syncPlatBtn(){
   const names = [...document.querySelectorAll('#s-plat-panel input:checked')]
     .map(x => CHANNELS.find(c => c.key === x.value).name);
-  $('#s-plat-btn').textContent = names.length ? names.join('、') + ' ▾' : '选择渠道 ▾';
+  $('#s-plat-btn').innerHTML =
+    `<span>${names.length ? esc(names.join('、')) : '选择渠道'}</span><span class="dd-arrow">▾</span>`;
 }
 $('#s-plat-btn').onclick = e => { e.stopPropagation(); $('#s-plat-panel').hidden = !$('#s-plat-panel').hidden; };
 $('#s-plat-panel').onclick = e => e.stopPropagation();