feat(tui): add terminal user interface with Ink

Add a full TUI for Claudeman using Ink (React for CLI):
- StartScreen: Shows existing sessions from screens.json
- TabBar: Session tabs with status indicators
- TerminalView: PTY output display with scrolling
- StatusBar: Session info and keyboard shortcuts
- HelpOverlay: Full keyboard shortcut reference

Features:
- Session discovery from ~/.claudeman/screens.json
- Tab navigation (Ctrl+Tab, Ctrl+1-9)
- Create new sessions (connects to web API)
- Kill sessions via screen commands
- Keyboard-driven navigation

Usage: claudeman tui

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

src/tui/components/index.ts

@@ -0,0 +1,9 @@
+/**
+ * @fileoverview Component exports for TUI
+ */
+
+export { StartScreen } from './StartScreen.js';
+export { TabBar } from './TabBar.js';
+export { TerminalView } from './TerminalView.js';
+export { StatusBar } from './StatusBar.js';
+export { HelpOverlay } from './HelpOverlay.js';