feat(ui): add collapsible persistent sidebar

src/components/sessions/WelcomeView.tsx

@@ -1,8 +1,9 @@
-import { Terminal, Plus, Zap, Clock, Server, ChevronRight } from 'lucide-react'
+import { Plus, Zap, Clock, Server, ChevronRight } from 'lucide-react'
 import { useSessionStore } from '../../stores'
 import { useTabStore } from '../../stores/tabStore'
 import EmptyState from '../common/EmptyState'
 import LocalShellMenu from '../layout/sidebar/LocalShellMenu'
+import appIconUrl from '../../assets/opsxshell-app-icon.png'
 
 interface WelcomeViewProps {
   onNewSession?: () => void
@@ -27,12 +28,17 @@ export default function WelcomeView({ onNewSession, onQuickConnect }: WelcomeVie
       <div className="w-full max-w-3xl px-6 py-10 sm:py-12">
         {/* Hero — 短文案 */}
         <div className="flex items-center gap-4 mb-8">
-          <div className="w-14 h-14 rounded-2xl bg-gradient-to-br from-accent-blue/30 to-accent-purple/20 border border-dark-600/60 flex items-center justify-center shadow-lg shadow-black/20 flex-shrink-0">
-            <Terminal className="w-7 h-7 text-content-primary" />
-          </div>
+          <img
+            src={appIconUrl}
+            alt="OpsXShell"
+            width={56}
+            height={56}
+            className="h-14 w-14 flex-shrink-0 rounded-2xl object-cover shadow-lg shadow-black/20"
+            draggable={false}
+          />
           <div className="min-w-0">
             <h1 className="text-2xl font-semibold text-content-primary tracking-tight">OpsXShell</h1>
-            <p className="text-sm text-txt-muted mt-0.5">SSH / SFTP 跨平台运维工作台</p>
+            <p className="text-sm text-txt-muted mt-0.5">SSH / SFTP 终端</p>
           </div>
         </div>