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>

src/stores/tabStore.ts

@@ -176,12 +176,25 @@ export const useTabStore = create<TabState>()(
 
       closeTab: (tabId) => {
         const { tabs, activeTabId } = get()
-        
-        if (tabs.length <= 1) return null
-        
         const closedTab = tabs.find(t => t.id === tabId) || null
+        if (!closedTab) return null
+
+        // Last remaining tab: welcome stays put; any other type resets to welcome
+        // (e.g. after "close others", closing the sole terminal must work).
+        if (tabs.length <= 1) {
+          if (closedTab.type === 'welcome') return null
+          const welcomeTab: Tab = {
+            id: 'welcome',
+            title: '欢迎',
+            type: 'welcome',
+            isActive: true,
+          }
+          set({ tabs: [welcomeTab], activeTabId: 'welcome' })
+          return closedTab
+        }
+
         const newTabs = tabs.filter(t => t.id !== tabId)
-        
+
         // If closing active tab, activate another one
         let newActiveId = activeTabId
         if (activeTabId === tabId) {
@@ -192,7 +205,7 @@ export const useTabStore = create<TabState>()(
             newActiveId = newActiveTab.id
           }
         }
-        
+
         set({ tabs: newTabs, activeTabId: newActiveId })
         return closedTab
       },