✨ feat(vscode): 工单挂原型插件，详情面板一键导入 Figma

- prototypeFile 走通 state → Issue → webview 全链路（gitea/youtrack 两个
  loader、两份 KNOWN_STATE_FIELDS、issue/patch、webview types），按 planFile
  同款当共享字段；路径校验换成 .json 版，允许绝对路径
- 详情面板「计划文件」下加「原型插件路径」行：双击开 manifest.json，
  行尾按钮「在 Figma 中导入并打开」；没挂插件时只显示空态
- src/figma/：把 manifest 写进 Figma 桌面版的 localFileExtensions 再拉起
  Figma。坑是 Figma 退出会用内存状态覆盖 settings.json，所以写之前先
  osascript 优雅退出并轮询等它真没了（10s 等不到就让用户手动关，不强杀）；
  写前备份 settings.json.bak-<时间戳>；已导入过就跳过写入直接打开；
  非 macOS 只把路径复制到剪贴板
- webhook 里 spec/plan 的 marker 同步改成表驱动，顺带认第三种 prototype
- 提示词：prototype.md 要求画完挂 marker；brainstorm-continue.md 新增
  {prototypeRef} 占位符，有原型插件时让续聊先读它别从零重画，没有时
  连同整段抹掉

Claude-Session: https://claude.ai/code/session_01Kgmb1LvrPmFX3NoUDB4zZC

vscode/webview-ui/src/hooks/useIssues.ts

@@ -200,6 +200,8 @@ export interface UseIssuesResult {
   resumePrototypeSession: (sessionId: string, issueNumber: number, cwd?: string) => void
   focusSession: (issueNumber: number) => void
   openFile: (path: string) => void
+  /** 把工单的 Figma 插件导入本机 Figma 桌面版并拉起 Figma。 */
+  openPrototypeInFigma: (issueNumber: number, path: string) => void
   implement: (issueNumber: number, planFile: string, profilePath?: string, sessionId?: string) => void
   generatePrDiffSummary: (issueNumber: number) => void
   isPrDiffSummaryRunning: (issueNumber: number) => boolean
@@ -588,6 +590,10 @@ export function useIssues(): UseIssuesResult {
     postMessage({ type: 'editor/open-file', path })
   }, [])
 
+  const openPrototypeInFigma = useCallback((issueNumber: number, path: string): void => {
+    postMessage({ type: 'prototype/open-in-figma', issueNumber, path })
+  }, [])
+
   const implement = useCallback((
     issueNumber: number,
     planFile: string,
@@ -1037,5 +1043,5 @@ export function useIssues(): UseIssuesResult {
     return cleanup
   }, [clearPrDiffSummaryRunning, markHandoffRunning])
 
-  return { state, settings, avatars, isSessionTabPending, globalAutoReview, youtrackConfigured, importYouTrack, toasts, profiles, setIssues, refresh, refreshing, scope, toggleScope, saveSettings, listYouTrackProjects, youtrackProjects, dismissSettings, requestEditAuth, createIssue, dismissToast, openUrl, resumeSession, resumeReviewSession, startReviewSession, startTestSession, resumeTestSession, startPrototypeSession, resumePrototypeSession, focusSession, openFile, implement, generatePrDiffSummary, isPrDiffSummaryRunning, openPr, openWorktree, deleteWorktree, mergeBranch, deleteIssue, closeIssue, closeSessionTab, continueBrainstorm, changeColumn, setDependency, clearDependency, updateIssueAutoReview, updateIssueProfilePath, updateIssueBrainstormProfilePath, clearBrainstormSession, updateIssueTestProfilePath, updateIssuePrototypeProfilePath, logs, fetchLogs, clearLogs, pendingSelectId, clearPendingSelect, commitRunning, runCommit, hasChanges, release, runRelease, cherryPick, dismissCherryPick, confirmCherryPick, envLocked, envFileCount, envLockRunning, envLockTitle, toggleEnvLock, me, handoffUsers, requestHandoffUsers, startHandoff, acceptHandoff, isHandoffRunning }
+  return { state, settings, avatars, isSessionTabPending, globalAutoReview, youtrackConfigured, importYouTrack, toasts, profiles, setIssues, refresh, refreshing, scope, toggleScope, saveSettings, listYouTrackProjects, youtrackProjects, dismissSettings, requestEditAuth, createIssue, dismissToast, openUrl, resumeSession, resumeReviewSession, startReviewSession, startTestSession, resumeTestSession, startPrototypeSession, resumePrototypeSession, focusSession, openFile, openPrototypeInFigma, implement, generatePrDiffSummary, isPrDiffSummaryRunning, openPr, openWorktree, deleteWorktree, mergeBranch, deleteIssue, closeIssue, closeSessionTab, continueBrainstorm, changeColumn, setDependency, clearDependency, updateIssueAutoReview, updateIssueProfilePath, updateIssueBrainstormProfilePath, clearBrainstormSession, updateIssueTestProfilePath, updateIssuePrototypeProfilePath, logs, fetchLogs, clearLogs, pendingSelectId, clearPendingSelect, commitRunning, runCommit, hasChanges, release, runRelease, cherryPick, dismissCherryPick, confirmCherryPick, envLocked, envFileCount, envLockRunning, envLockTitle, toggleEnvLock, me, handoffUsers, requestHandoffUsers, startHandoff, acceptHandoff, isHandoffRunning }
 }