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/ui/AppContainer.test.tsx

@@ -78,6 +78,24 @@ vi.mock('./hooks/useAutoAcceptIndicator.js');
 vi.mock('./hooks/useGitBranchName.js');
 vi.mock('./contexts/VimModeContext.js');
 vi.mock('./contexts/SessionContext.js');
+vi.mock('./contexts/AgentViewContext.js', () => ({
+  useAgentViewState: vi.fn(() => ({
+    activeView: 'main',
+    agents: new Map(),
+  })),
+  useAgentViewActions: vi.fn(() => ({
+    switchToMain: vi.fn(),
+    switchToAgent: vi.fn(),
+    switchToNext: vi.fn(),
+    switchToPrevious: vi.fn(),
+    registerAgent: vi.fn(),
+    unregisterAgent: vi.fn(),
+    unregisterAll: vi.fn(),
+  })),
+}));
+vi.mock('./hooks/useArenaInProcess.js', () => ({
+  useArenaInProcess: vi.fn(),
+}));
 vi.mock('./components/shared/text-buffer.js');
 vi.mock('./hooks/useLogger.js');