fix: allow closing last session tab and restore DevTools shortcut

Closing the sole remaining non-welcome tab now resets to welcome; enable Tauri devtools, menu/shortcut toggle, and copy release artifacts from CARGO_TARGET_DIR.

Co-authored-by: Cursor <cursoragent@cursor.com>

test/setup.ts

@@ -127,6 +127,7 @@ export const mockDesktopApi: DesktopApiContract = {
   clipboardReadText: vi.fn().mockResolvedValue(''),
   clipboardWriteText: vi.fn().mockResolvedValue(undefined),
   toggleMaximize: vi.fn().mockResolvedValue(undefined),
+  toggleDevtools: vi.fn().mockResolvedValue(false),
 
   // Local terminal
   localListShells: vi.fn().mockResolvedValue({

test/stores/tabStore.test.ts

@@ -72,15 +72,32 @@ describe('TabStore', () => {
   })
 
   describe('closeTab', () => {
-    it('不应该关闭最后一个标签', () => {
+    it('不应该关闭最后一个欢迎页', () => {
       const { closeTab } = useTabStore.getState()
       const closed = closeTab('welcome')
 
       const { tabs } = useTabStore.getState()
       expect(tabs).toHaveLength(1)
+      expect(tabs[0].type).toBe('welcome')
       expect(closed).toBeNull()
     })
 
+    it('关闭最后一个会话标签应回到欢迎页', () => {
+      const { addTab, closeOtherTabs, closeTab } = useTabStore.getState()
+      addTab({ title: 'Tab 1', type: 'terminal' })
+      const session = useTabStore.getState().tabs.find((t) => t.title === 'Tab 1')
+      expect(session).toBeTruthy()
+      closeOtherTabs(session!.id)
+
+      expect(useTabStore.getState().tabs).toHaveLength(1)
+      const closed = closeTab(session!.id)
+      const { tabs, activeTabId } = useTabStore.getState()
+      expect(closed?.title).toBe('Tab 1')
+      expect(tabs).toHaveLength(1)
+      expect(tabs[0].type).toBe('welcome')
+      expect(activeTabId).toBe('welcome')
+    })
+
     it('关闭标签后应该激活另一个标签', () => {
       const { addTab, closeTab } = useTabStore.getState()
       addTab({ title: 'Tab 1', type: 'terminal' })