feat(dev): improve dev runner with PTY support, scrolling, and CI tasks

[Gaubee]

Summary

• Rewrite dev.ts to single-file using Bun.Terminal for true PTY support
• Add focus mode (Enter to enter, Ctrl+] to exit) for interactive stdin
• Add scrolling support (Page Up/Down, Home/End, arrow keys) with scrollbar
• Add dynamic help bar based on context
• Add non-TTY support with --help output
• Fix Option+arrow key tab switching
• Fix user-stopped process showing as error instead of stopped

New Tasks Added

Task	Command	Description
test	pnpm vitest --watch	Vitest watch
storybook	pnpm storybook	Storybook dev
docs	pnpm docs:dev	VitePress docs
mock	pnpm dev:mock	Vite mock mode
lint	pnpm lint	Oxlint check
i18n:check	pnpm i18n:run	i18n validation
theme:check	pnpm theme:run	Theme check
build	pnpm build	Vite build
e2e:audit	pnpm e2e:audit:run	E2E audit

Key Bindings

• Option+←/→: Switch tabs
• ↑/↓: Navigate/scroll
• Page Up/Down: Page scroll
• Home/End: Scroll to top/bottom
• Enter: Start task / Enter focus mode
• Ctrl+]: Exit focus mode
• S/R/Q: Stop/Restart/Quit
• A/X: Start all / Stop all