diff --git a/CHANGELOG.md b/CHANGELOG.md
index 5fd6f4b..dfb0f6c 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -13,6 +13,9 @@
 ### Fixed
 
 - 新增 `.gitattributes` 统一文本文件为 `LF`，修复 Windows CI 中 `Prettier --check` 因 `CRLF` 检出导致的格式校验失败。
+- 修复终态任务仍可再次触发 `Approve and run` 的问题，主进程会将其视为 no-op，渲染层也会在任务进入终态后禁用执行按钮。
+- 修复 `Claude Code CLI` 适配器在同一 session 重复执行时复用事件 ID 的问题，避免时间线渲染出现重复 key。
+- 为桌面主窗口补充受信导航策略，仅允许本地 `file://` 或开发服务器地址留在应用内，其它链接统一改走系统浏览器。
 
 ## [0.1.0] - 2026-03-25
 
diff --git a/apps/desktop/src/main/app/bootstrapDesktopApp.ts b/apps/desktop/src/main/app/bootstrapDesktopApp.ts
index eab864b..a69e5db 100644
--- a/apps/desktop/src/main/app/bootstrapDesktopApp.ts
+++ b/apps/desktop/src/main/app/bootstrapDesktopApp.ts
@@ -8,6 +8,7 @@ import { registerDesktopIpcHandlers } from '../ipc/registerDesktopIpcHandlers'
 import { FileDesktopStore } from '../persistence/fileDesktopStore'
 import { SQLiteDesktopStore } from '../persistence/sqliteDesktopStore'
 import { DesktopController } from '../services/desktopController'
+import { isTrustedDesktopUrl } from './navigationPolicy'
 
 declare const MAIN_WINDOW_VITE_DEV_SERVER_URL: string | undefined
 declare const MAIN_WINDOW_VITE_NAME: string
@@ -29,6 +30,31 @@ const createMainWindow = () => {
     }
   })
 
+  const handleExternalNavigation = (url: string) => {
+    if (isTrustedDesktopUrl(url, MAIN_WINDOW_VITE_DEV_SERVER_URL)) {
+      return
+    }
+
+    void shell.openExternal(url)
+  }
+
+  mainWindow.webContents.setWindowOpenHandler(({ url }) => {
+    handleExternalNavigation(url)
+
+    return {
+      action: isTrustedDesktopUrl(url, MAIN_WINDOW_VITE_DEV_SERVER_URL) ? 'allow' : 'deny'
+    }
+  })
+
+  mainWindow.webContents.on('will-navigate', (event, url) => {
+    if (isTrustedDesktopUrl(url, MAIN_WINDOW_VITE_DEV_SERVER_URL)) {
+      return
+    }
+
+    event.preventDefault()
+    handleExternalNavigation(url)
+  })
+
   if (MAIN_WINDOW_VITE_DEV_SERVER_URL) {
     void mainWindow.loadURL(MAIN_WINDOW_VITE_DEV_SERVER_URL)
     mainWindow.webContents.openDevTools({ mode: 'detach' })
diff --git a/apps/desktop/src/main/app/navigationPolicy.test.ts b/apps/desktop/src/main/app/navigationPolicy.test.ts
new file mode 100644
index 0000000..246ca6f
--- /dev/null
+++ b/apps/desktop/src/main/app/navigationPolicy.test.ts
@@ -0,0 +1,19 @@
+// @vitest-environment node
+
+import { describe, expect, it } from 'vitest'
+
+import { isTrustedDesktopUrl } from './navigationPolicy'
+
+describe('isTrustedDesktopUrl', () => {
+  it('allows only the configured dev server during local development', () => {
+    expect(isTrustedDesktopUrl('http://127.0.0.1:5173/', 'http://127.0.0.1:5173')).toBe(true)
+    expect(isTrustedDesktopUrl('https://github.com/FruitsAI/Mango', 'http://127.0.0.1:5173')).toBe(
+      false
+    )
+  })
+
+  it('allows packaged file urls in production builds', () => {
+    expect(isTrustedDesktopUrl('file:///C:/Program%20Files/Mango/index.html')).toBe(true)
+    expect(isTrustedDesktopUrl('https://example.com')).toBe(false)
+  })
+})
diff --git a/apps/desktop/src/main/app/navigationPolicy.ts b/apps/desktop/src/main/app/navigationPolicy.ts
new file mode 100644
index 0000000..3525f36
--- /dev/null
+++ b/apps/desktop/src/main/app/navigationPolicy.ts
@@ -0,0 +1,7 @@
+export const isTrustedDesktopUrl = (url: string, devServerUrl?: string): boolean => {
+  if (devServerUrl) {
+    return url.startsWith(devServerUrl)
+  }
+
+  return url.startsWith('file://')
+}
diff --git a/apps/desktop/src/main/services/desktopController.test.ts b/apps/desktop/src/main/services/desktopController.test.ts
index fb97006..2b58c4e 100644
--- a/apps/desktop/src/main/services/desktopController.test.ts
+++ b/apps/desktop/src/main/services/desktopController.test.ts
@@ -150,4 +150,30 @@ describe('DesktopController', () => {
       level: 'error'
     })
   })
+
+  it('treats approve and run as a no-op once the active task has already finished', async () => {
+    const store = new MemoryDesktopStore(createPersistedState())
+    const controller = new DesktopController(store, [
+      new FakeAdapter('claude-code', 'Claude Code CLI'),
+      new FakeAdapter('mock-claude', 'Mock Claude CLI')
+    ])
+
+    await controller.generatePlan({
+      prompt: 'Implement adapter registry',
+      workspaceId: workspace.id,
+      adapterId: 'claude-code'
+    })
+
+    const completedState = await controller.approveAndRun()
+    const repeatedState = await controller.approveAndRun()
+
+    expect(completedState.activeTask?.status).toBe('succeeded')
+    expect(repeatedState.activeTask?.status).toBe('succeeded')
+    expect(repeatedState.activeTask?.events).toHaveLength(
+      completedState.activeTask?.events.length ?? 0
+    )
+    expect(repeatedState.activeTask?.executionSummary).toBe(
+      completedState.activeTask?.executionSummary
+    )
+  })
 })
diff --git a/apps/desktop/src/main/services/desktopController.ts b/apps/desktop/src/main/services/desktopController.ts
index 0271442..729410c 100644
--- a/apps/desktop/src/main/services/desktopController.ts
+++ b/apps/desktop/src/main/services/desktopController.ts
@@ -152,12 +152,13 @@ export class DesktopController {
 
   public async approveAndRun(): Promise<DesktopState> {
     const persisted = await this.ensureState()
+    const activeTask = persisted.activeTask
 
-    if (!persisted.activeTask?.plan) {
+    if (!activeTask?.plan || !['planned', 'approved'].includes(activeTask.status)) {
       return this.buildDesktopState(persisted)
     }
 
-    let session = persisted.activeTask
+    let session = activeTask
 
     if (session.status === 'planned') {
       session = applyTaskTransition(session, {
diff --git a/apps/desktop/src/renderer/src/features/task-workbench/TaskWorkbench.tsx b/apps/desktop/src/renderer/src/features/task-workbench/TaskWorkbench.tsx
index 3ddd99e..62b8a5d 100644
--- a/apps/desktop/src/renderer/src/features/task-workbench/TaskWorkbench.tsx
+++ b/apps/desktop/src/renderer/src/features/task-workbench/TaskWorkbench.tsx
@@ -51,6 +51,9 @@ export const TaskWorkbench = ({
     selectedAdapterId ?? selectedWorkspace?.providerConfig?.primaryAdapterId
   )
   const activePlan = state.activeTask?.plan
+  const canApproveAndRun =
+    Boolean(activePlan) &&
+    (state.activeTask?.status === 'planned' || state.activeTask?.status === 'approved')
 
   return (
     <div className="shell">
@@ -178,7 +181,7 @@ export const TaskWorkbench = ({
               </button>
               <button
                 className="secondary-button"
-                disabled={busy || !state.activeTask?.plan}
+                disabled={busy || !canApproveAndRun}
                 onClick={onApproveAndRun}
                 type="button"
               >
diff --git a/apps/desktop/src/renderer/src/test/App.test.tsx b/apps/desktop/src/renderer/src/test/App.test.tsx
index 65660da..ad02003 100644
--- a/apps/desktop/src/renderer/src/test/App.test.tsx
+++ b/apps/desktop/src/renderer/src/test/App.test.tsx
@@ -78,4 +78,10 @@ describe('TaskWorkbench', () => {
       screen.getByText('Claude Code CLI is available for local Mango execution.')
     ).toBeInTheDocument()
   })
+
+  it('disables approve and run after the task has already reached a terminal state', () => {
+    render(<TaskWorkbench state={buildMockDesktopState()} />)
+
+    expect(screen.getByRole('button', { name: /approve and run/i })).toBeDisabled()
+  })
 })
diff --git a/packages/adapters/src/claudeCodeCliAdapter.ts b/packages/adapters/src/claudeCodeCliAdapter.ts
index 56e8e6e..64e3f51 100644
--- a/packages/adapters/src/claudeCodeCliAdapter.ts
+++ b/packages/adapters/src/claudeCodeCliAdapter.ts
@@ -1,3 +1,4 @@
+import { randomUUID } from 'node:crypto'
 import { execFile } from 'node:child_process'
 import { promisify } from 'node:util'
 
@@ -94,6 +95,9 @@ const planSchema = {
 const timestamp = (offsetMilliseconds = 0): string =>
   new Date(Date.now() + offsetMilliseconds).toISOString()
 
+const createExecutionEventId = (sessionId: string, suffix: string): string =>
+  `${sessionId}-${randomUUID()}-${suffix}`
+
 const normalizeText = (value: string): string => value.trim()
 
 const buildCommandErrorMessage = (
@@ -272,14 +276,14 @@ export class ClaudeCodeCliAdapter implements AgentAdapter {
     return [
       {
         type: 'terminal.output',
-        id: `${input.sessionId}-claude-output`,
+        id: createExecutionEventId(input.sessionId, 'claude-output'),
         level: 'info',
         message: `${this.label} completed the approved run`,
         createdAt: timestamp()
       },
       {
         type: 'summary.ready',
-        id: `${input.sessionId}-claude-summary`,
+        id: createExecutionEventId(input.sessionId, 'claude-summary'),
         level: 'info',
         message: `${this.label} summary ready`,
         summary,
diff --git a/packages/adapters/tests/claudeCodeCliAdapter.test.ts b/packages/adapters/tests/claudeCodeCliAdapter.test.ts
index 17c116a..e35e34a 100644
--- a/packages/adapters/tests/claudeCodeCliAdapter.test.ts
+++ b/packages/adapters/tests/claudeCodeCliAdapter.test.ts
@@ -124,4 +124,28 @@ describe('ClaudeCodeCliAdapter', () => {
       })
     )
   })
+
+  it('emits unique event ids across repeated approved runs for the same session', async () => {
+    const commandRunner = vi.fn(async () => ({
+      exitCode: 0,
+      stdout: 'Updated the adapter registry and verified the desktop workflow.',
+      stderr: ''
+    }))
+    const adapter = new ClaudeCodeCliAdapter({
+      commandRunner
+    })
+
+    const firstRunEvents = await adapter.runApprovedPlan({
+      sessionId: 'session-1',
+      prompt: 'Implement adapter registry',
+      workspace
+    })
+    const secondRunEvents = await adapter.runApprovedPlan({
+      sessionId: 'session-1',
+      prompt: 'Implement adapter registry',
+      workspace
+    })
+
+    expect(new Set([...firstRunEvents, ...secondRunEvents].map((event) => event.id)).size).toBe(4)
+  })
 })