feat(cli): Add agent tab navigation and live tool output for in-process arena mode

Add AgentViewContext, AgentTabBar, and AgentChatView components for tab-based
agent switching. Add useArenaInProcess hook bridging ArenaManager events to
React state. Add agentHistoryAdapter converting AgentMessage[] to HistoryItem[].

Core support changes:
- Replace stream buffers with ROUND_TEXT events (complete round text)
- Add TOOL_OUTPUT_UPDATE events for live tool output streaming
- Add pendingApprovals/liveOutputs/shellPids state to AgentInteractive
- Fix missing ROUND_END emission for final text rounds

Co-authored-by: Qwen-Coder <qwen-coder@alibabacloud.com>

packages/cli/src/gemini.tsx

@@ -35,6 +35,7 @@ import { KeypressProvider } from './ui/contexts/KeypressContext.js';
 import { SessionStatsProvider } from './ui/contexts/SessionContext.js';
 import { SettingsContext } from './ui/contexts/SettingsContext.js';
 import { VimModeProvider } from './ui/contexts/VimModeContext.js';
+import { AgentViewProvider } from './ui/contexts/AgentViewContext.js';
 import { useKittyKeyboardProtocol } from './ui/hooks/useKittyKeyboardProtocol.js';
 import { themeManager } from './ui/themes/theme-manager.js';
 import { detectAndEnableKittyProtocol } from './ui/utils/kittyProtocolDetector.js';
@@ -162,13 +163,15 @@ export async function startInteractiveUI(
         >
           <SessionStatsProvider sessionId={config.getSessionId()}>
             <VimModeProvider settings={settings}>
-              <AppContainer
-                config={config}
-                settings={settings}
-                startupWarnings={startupWarnings}
-                version={version}
-                initializationResult={initializationResult}
-              />
+              <AgentViewProvider>
+                <AppContainer
+                  config={config}
+                  settings={settings}
+                  startupWarnings={startupWarnings}
+                  version={version}
+                  initializationResult={initializationResult}
+                />
+              </AgentViewProvider>
             </VimModeProvider>
           </SessionStatsProvider>
         </KeypressProvider>