✨ feat(vscode): 移交/接管扩展端流程与消息分发

Claude-Session: https://claude.ai/code/session_011cEyL6k351U2BzX1Qmygph

vscode/src/panel/KanbanPanel.ts

@@ -27,6 +27,7 @@ import { annotateReviewSessionFileExists } from '../sessions/codexSessions'
 import { getEffectiveCommitProfilePath, getSettings } from '../settings/store'
 import { webhookCoordinator } from '../webhook/coordinator'
 import { loadYouTrackIssues } from '../youtrack/issueLoader'
+import * as handoffFlow from './handlers/handoffFlow'
 import * as issues from './handlers/issues'
 import * as managedSessions from './handlers/managedSessions'
 import * as prFiles from './handlers/prFiles'
@@ -427,6 +428,18 @@ export class KanbanWebviewPanel {
         void issues.handleColumnChange(this, msg.issueNumber, msg.toColumn)
       return
     }
+    if (msg.type === 'handoff/users') {
+      void handoffFlow.handleHandoffUsers(this, msg.issueNumber)
+      return
+    }
+    if (msg.type === 'handoff/start') {
+      void handoffFlow.handleHandoffStart(this, msg.issueNumber, msg.to)
+      return
+    }
+    if (msg.type === 'handoff/accept') {
+      void handoffFlow.handleHandoffAccept(this, msg.issueNumber)
+      return
+    }
     if (msg.type === 'youtrack/list-projects') {
       void youtrackIssues.handleListProjects(this, msg.baseUrl, msg.token)
       return