✨ feat(vscode): 看板顶部加筛选框，按标题 / 工单号 / PR 号过滤卡片

工单多了以后靠肉眼在四列里翻太慢。顶部输入框按空白分词逐词 AND 匹配
标题、工单号、PR 号，`#427` 与 `427` 等价，纯数字按包含匹配，记不全
编号也能搜到。筛选只收窄渲染，拖拽与依赖锁定仍按全量列表算；列头角标
在筛选时显示「可见 / 总数」。

vscode/webview-ui/src/lib/issueFilter.test.ts

@@ -0,0 +1,60 @@
+import type { Issue } from '../types'
+import { describe, expect, it } from 'vitest'
+import { filterIssues } from './issueFilter'
+
+function issue(number: number, title: string, extra: Partial<Issue> = {}): Issue {
+  return {
+    id: `repo#${number}`,
+    number,
+    title,
+    column: 'todo',
+    htmlUrl: '',
+    ...extra,
+  }
+}
+
+const board = [
+  issue(426, '编程大赛：报名与提交作品'),
+  issue(427, '编程大赛-作品墙分类', { pr: '318' }),
+  issue(419, '管理后台统计各模型用量'),
+  issue(42, 'auto 模型：自动为用户会话选模型'),
+]
+
+function numbers(query: string): number[] {
+  return filterIssues(board, query).map(i => i.number)
+}
+
+describe('filterIssues', () => {
+  it('空查询放行全部，且原样返回同一个数组', () => {
+    expect(filterIssues(board, '   ')).toBe(board)
+  })
+
+  it('按标题子串匹配', () => {
+    expect(numbers('作品')).toEqual([426, 427])
+  })
+
+  it('标题匹配不区分大小写', () => {
+    expect(numbers('AUTO')).toEqual([42])
+  })
+
+  it('按工单号匹配，带不带 # 都行', () => {
+    expect(numbers('#427')).toEqual([427])
+    expect(numbers('427')).toEqual([427])
+  })
+
+  it('数字按包含匹配，短号能带出长号', () => {
+    expect(numbers('42')).toEqual([426, 427, 42])
+  })
+
+  it('按 PR 号匹配', () => {
+    expect(numbers('318')).toEqual([427])
+  })
+
+  it('多个词之间是 AND', () => {
+    expect(numbers('编程 分类')).toEqual([427])
+  })
+
+  it('没有命中时返回空', () => {
+    expect(numbers('不存在的东西')).toEqual([])
+  })
+})

vscode/webview-ui/src/lib/issueFilter.ts

@@ -0,0 +1,34 @@
+import type { Issue } from '../types'
+
+/**
+ * 看板顶部筛选框的匹配规则。
+ *
+ * 查询按空白切成多个词，逐词 AND：工单要留在板上，每个词都得命中它的
+ * 标题、工单号或 PR 号之一。词首的 `#` 先去掉，`#427` 与 `427` 等价。
+ * 纯数字的词按「包含」匹配编号，`42` 既能带出 #42 也能带出 #427，
+ * 免得用户记不全编号就搜不到。
+ */
+export function parseFilterTerms(query: string): string[] {
+  return query.trim().toLowerCase().split(/\s+/).filter(Boolean)
+}
+
+function matchesTerm(issue: Issue, term: string): boolean {
+  if (issue.title.toLowerCase().includes(term))
+    return true
+  const digits = term.replace(/^#/, '')
+  if (digits === '' || !/^\d+$/.test(digits))
+    return false
+  return String(issue.number).includes(digits) || (issue.pr ?? '').includes(digits)
+}
+
+export function matchesIssueFilter(issue: Issue, terms: string[]): boolean {
+  return terms.every(term => matchesTerm(issue, term))
+}
+
+/** 空查询原样返回，调用方据此免掉一次无意义的数组拷贝。 */
+export function filterIssues(issues: Issue[], query: string): Issue[] {
+  const terms = parseFilterTerms(query)
+  if (terms.length === 0)
+    return issues
+  return issues.filter(issue => matchesIssueFilter(issue, terms))
+}