feat(V0.2): 看板列内纵向滚动加固 + 滚动时右缘滚动条 (方案 B)

- 列体外包 .bcol-main (relative): 叠加自绘细滚动条, 滚动时出现、
  停止约 700ms 后淡出, 宽 3px 不占卡片空间
- bcol-body 补 -webkit-overflow-scrolling/overscroll-behavior,
  高度链显式化 (height:100%), 修真机列内滚不动的问题
- 列头保持固定不随滚动

src/pages/task/BoardView.jsx

@@ -1,8 +1,39 @@
+import { useEffect, useRef, useState } from 'react'
 import TaskCard from '../../components/task/TaskCard.jsx'
 import useColumnDrag from '../../components/task/useColumnDrag.js'
 
+// 列体 + 右缘滚动条: 滚动时出现细滚动条, 停止约 700ms 后淡出
+// (移动端 WebView 原生滚动条是即隐式的, 看板列窄、需要明确的滚动指示)
+function ScrollBody({ children }) {
+  const ref = useRef(null)
+  const fade = useRef(null)
+  const [bar, setBar] = useState(null) // { h, y } 滚动条几何
+
+  useEffect(() => () => clearTimeout(fade.current), [])
+
+  function onScroll() {
+    const el = ref.current
+    if (!el) return
+    const max = el.scrollHeight - el.clientHeight
+    if (max <= 2) { setBar(null); return }
+    const h = Math.max(28, Math.round(el.clientHeight * (el.clientHeight / el.scrollHeight)))
+    const y = Math.round((el.scrollTop / max) * (el.clientHeight - h))
+    setBar({ h, y })
+    clearTimeout(fade.current)
+    fade.current = setTimeout(() => setBar(null), 700)
+  }
+
+  return (
+    <div className="bcol-main">
+      <div className="bcol-body" ref={ref} onScroll={onScroll}>{children}</div>
+      <div className={'bcol-bar' + (bar ? ' on' : '')} style={bar ? { top: bar.y, height: bar.h } : undefined} />
+    </div>
+  )
+}
+
 // 看板视图 (T-BD-01, T-UI-07)
 //   拖动 = 长按 400ms 激活, 卡片原位抬起, 指针划过列高亮, 松手落列 (重点设计 §7.1)
+//   横向滚列; 列内独立纵向滚动, 列头固定, 滚动时右缘显示滚动条
 //   不做"拖到卡片上转子任务" —— 统一走详情页「转为子任务」
 export default function BoardView({
   tasks, columns, onMoveColumn, onOpen, onToggleSub, onToggle, onMore, onQuickAdd,
@@ -33,7 +64,7 @@ export default function BoardView({
               )}
             </div>
 
-            <div className="bcol-body">
+            <ScrollBody>
               {list.map((t) => (
                 <TaskCard
                   key={t.id}
@@ -48,7 +79,7 @@ export default function BoardView({
               ))}
               {list.length === 0 && <div className="bcol-empty">暂无任务</div>}
               <div className="badd" onClick={() => onQuickAdd?.(col.id)}>+ 添加任务</div>
-            </div>
+            </ScrollBody>
           </div>
         )
       })}

src/styles/globals.css

@@ -1077,13 +1077,24 @@ body.me-safe-top .app-safe-top { height: 0; }
   display: flex; gap: 10px; padding: 0 12px 8px; overflow-x: auto; overflow-y: hidden;
   flex: 1 1 auto; min-height: 0; align-items: stretch;
 }
-.bcol { flex: 0 0 186px; display: flex; flex-direction: column; min-height: 0; }
-.bcol-head { display: flex; align-items: center; gap: 5px; padding: 0 2px 7px; flex-shrink: 0; }
+.bcol { flex: 0 0 186px; display: flex; flex-direction: column; min-height: 0; }.bcol-head { display: flex; align-items: center; gap: 5px; padding: 0 2px 7px; flex-shrink: 0; }
 .bcol-name { font-size: 12px; font-weight: 700; color: #3d4450; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
 .bcol-cnt { font-size: 11px; color: #999; background: #e8ebef; border-radius: 999px; padding: 0 6px; line-height: 15px; }
 .bcol-bind { font-size: 10px; color: var(--color-primary); background: #f0f5ff; border-radius: 4px; padding: 0 4px; margin-left: auto; }
 .bcol-bind.off { color: #999; background: #f2f3f5; }
-.bcol-body { flex: 1 1 auto; min-height: 0; overflow-y: auto; display: flex; flex-direction: column; gap: 7px; padding-bottom: 8px; }
+.bcol-body {
+  flex: 1 1 auto; min-height: 0; height: 100%; overflow-y: auto;
+  display: flex; flex-direction: column; gap: 7px; padding-bottom: 8px;
+  -webkit-overflow-scrolling: touch; overscroll-behavior: contain;
+}
+/* 列体包裹层: 承载右缘滚动条 (滚动时出现, 停止后淡出) */
+.bcol-main { flex: 1 1 auto; min-height: 0; position: relative; display: flex; }
+.bcol-bar {
+  position: absolute; right: 1px; width: 3px; border-radius: 2px;
+  background: rgba(15, 23, 42, .3); opacity: 0; transition: opacity .25s ease;
+  pointer-events: none; z-index: 3;
+}
+.bcol-bar.on { opacity: 1; }
 .bcol.dragover .bcol-body { background: #eaf2ff; border-radius: 8px; outline: 1.5px dashed var(--color-primary); }
 .bcol-empty { font-size: 11px; color: #c0c4cc; text-align: center; padding: 10px 0; }
 .bcard {