diff --git a/vscode/src/panel/handlers/issues.ts b/vscode/src/panel/handlers/issues.ts
index 794f641..c88e21a 100644
--- a/vscode/src/panel/handlers/issues.ts
+++ b/vscode/src/panel/handlers/issues.ts
@@ -541,16 +541,16 @@ export async function handleColumnChange(panel: KanbanWebviewPanel, issueNumber:
     })
   }
 
-  // 6. 全部成功 → 增量推 done + 清掉 worktreePath/branch + 标记 prMerged。
-  // webview 端 `{ ...issue, ...patch }` spread 会把 worktreePath 覆盖成
-  // undefined，详情面板的 worktree 链接行因此消失。
+  // 6. 全部成功 → 增量推 done + 用 null 清空 worktreePath/branch（postMessage 会丢 undefined key）
+  // 并带 worktreeExists: false，详情「工作树」行即时变为只读/—。
   panel.postMessage({
     type: 'issue/patch',
     issueNumber,
     patch: {
       column: 'done',
-      worktreePath: undefined,
-      branch: undefined,
+      worktreePath: null,
+      branch: null,
+      worktreeExists: false,
       prMerged: true,
       prMergedAt: pullRequest.merged_at ?? new Date().toISOString(),
     },
diff --git a/vscode/src/panel/handlers/worktree.ts b/vscode/src/panel/handlers/worktree.ts
index affeafb..f7ef9d3 100644
--- a/vscode/src/panel/handlers/worktree.ts
+++ b/vscode/src/panel/handlers/worktree.ts
@@ -144,12 +144,13 @@ export async function handleDeleteWorktree(panel: KanbanWebviewPanel, issueNumbe
     token,
   })
 
+  // null 才能过 postMessage 序列化；undefined 会被丢掉，webview 合并不清字段
   panel.postMessage({
     type: 'issue/patch',
     issueNumber,
     patch: {
-      worktreePath: undefined,
-      branch: undefined,
+      worktreePath: null,
+      branch: null,
       worktreeExists: false,
     },
   })
diff --git a/vscode/src/panel/messages.ts b/vscode/src/panel/messages.ts
index 075a260..e48708c 100644
--- a/vscode/src/panel/messages.ts
+++ b/vscode/src/panel/messages.ts
@@ -42,7 +42,7 @@ export type ExtensionToWebview
   = | { type: 'issues/loading' }
     | { type: 'issues/update', issues: Issue[], globalAutoReview: boolean, youtrackConfigured: boolean }
     | { type: 'issues/error', message: string }
-    | { type: 'issue/patch', issueNumber: number, patch: { autoReview?: boolean, specFile?: string, planFile?: string, prDiffFile?: string, sessionId?: string, implementSessionId?: string, reviewSessionId?: string, testSessionId?: string, pr?: string, implementStatus?: 'running' | 'done' | 'failed', column?: IssueColumn, worktreePath?: string, prMerged?: boolean, prMergedAt?: string, branch?: string, color?: string, worktreeExists?: boolean, brainstormTabOpen?: boolean, implementTabOpen?: boolean, reviewTabOpen?: boolean, testTabOpen?: boolean, profilePath?: string, brainstormProfilePath?: string, testProfilePath?: string } }
+    | { type: 'issue/patch', issueNumber: number, patch: { autoReview?: boolean, specFile?: string, planFile?: string, prDiffFile?: string, sessionId?: string, implementSessionId?: string, reviewSessionId?: string, testSessionId?: string, pr?: string | null, implementStatus?: 'running' | 'done' | 'failed', column?: IssueColumn, worktreePath?: string | null, prMerged?: boolean, prMergedAt?: string, branch?: string | null, color?: string, worktreeExists?: boolean, brainstormTabOpen?: boolean, implementTabOpen?: boolean, reviewTabOpen?: boolean, testTabOpen?: boolean, profilePath?: string, brainstormProfilePath?: string, testProfilePath?: string } }
     | { type: 'issue/pr-diff-summary-done', issueNumber: number }
     | { type: 'issue/append', issue: Issue, select?: boolean }
     | { type: 'issue/select-by-number', issueNumber: number }
diff --git a/vscode/src/webhook/coordinator.ts b/vscode/src/webhook/coordinator.ts
index 0a25e0b..41b7012 100644
--- a/vscode/src/webhook/coordinator.ts
+++ b/vscode/src/webhook/coordinator.ts
@@ -1062,7 +1062,8 @@ class WebhookCoordinator {
         this.activePanel.postMessage({
           type: 'issue/patch',
           issueNumber: event.issueNumber,
-          patch: { pr: undefined },
+          // null 才能过 postMessage；undefined 会被序列化丢掉
+          patch: { pr: null },
         })
       }
       catch (err) {
diff --git a/vscode/webview-ui/src/hooks/useIssues.ts b/vscode/webview-ui/src/hooks/useIssues.ts
index 41b5360..7b891f3 100644
--- a/vscode/webview-ui/src/hooks/useIssues.ts
+++ b/vscode/webview-ui/src/hooks/useIssues.ts
@@ -23,6 +23,16 @@ import type { LogEntry } from '../lib/messages'
 import { compareIssuesInColumn } from '../lib/issueSort'
 import { onMessage, postMessage } from '../lib/vscode'
 
+/** postMessage 用 null 清空 optional 字段；合并时 delete 还原 optional，避免残留 null */
+function applyIssuePatch(issue: Issue, patch: Record<string, unknown>): Issue {
+  const next = { ...issue, ...patch } as Issue & Record<string, unknown>
+  for (const [k, v] of Object.entries(patch)) {
+    if (v === null)
+      delete next[k]
+  }
+  return next as Issue
+}
+
 export interface SettingsValues {
   host: string
   token: string
@@ -560,7 +570,7 @@ export function useIssues(): UseIssuesResult {
             return {
               status: 'ready',
               issues: prev.issues.map(i =>
-                i.number === msg.issueNumber ? { ...i, ...msg.patch } : i,
+                i.number === msg.issueNumber ? applyIssuePatch(i, msg.patch) : i,
               ),
             }
           })
diff --git a/vscode/webview-ui/src/lib/messages.ts b/vscode/webview-ui/src/lib/messages.ts
index f0c4419..05824b2 100644
--- a/vscode/webview-ui/src/lib/messages.ts
+++ b/vscode/webview-ui/src/lib/messages.ts
@@ -57,7 +57,7 @@ export type ExtensionToWebview
   = | { type: 'issues/loading' }
     | { type: 'issues/update', issues: Issue[], globalAutoReview: boolean, youtrackConfigured: boolean }
     | { type: 'issues/error', message: string }
-    | { type: 'issue/patch', issueNumber: number, patch: { autoReview?: boolean, specFile?: string, planFile?: string, prDiffFile?: string, sessionId?: string, implementSessionId?: string, reviewSessionId?: string, testSessionId?: string, pr?: string, implementStatus?: 'running' | 'done' | 'failed', column?: IssueColumn, worktreePath?: string, prMerged?: boolean, prMergedAt?: string, branch?: string, color?: string, worktreeExists?: boolean, brainstormTabOpen?: boolean, implementTabOpen?: boolean, reviewTabOpen?: boolean, testTabOpen?: boolean, profilePath?: string, brainstormProfilePath?: string, testProfilePath?: string } }
+    | { type: 'issue/patch', issueNumber: number, patch: { autoReview?: boolean, specFile?: string, planFile?: string, prDiffFile?: string, sessionId?: string, implementSessionId?: string, reviewSessionId?: string, testSessionId?: string, pr?: string | null, implementStatus?: 'running' | 'done' | 'failed', column?: IssueColumn, worktreePath?: string | null, prMerged?: boolean, prMergedAt?: string, branch?: string | null, color?: string, worktreeExists?: boolean, brainstormTabOpen?: boolean, implementTabOpen?: boolean, reviewTabOpen?: boolean, testTabOpen?: boolean, profilePath?: string, brainstormProfilePath?: string, testProfilePath?: string } }
     | { type: 'issue/pr-diff-summary-done', issueNumber: number }
     | { type: 'issue/append', issue: Issue, select?: boolean }
     | { type: 'issue/select-by-number', issueNumber: number }