fix(packages/cli): dev server requires two Ctrl+C presses to exit

[zrosenbauer]

Summary

The zpress dev server does not exit on the first Ctrl+C — it requires pressing Ctrl+C twice to terminate the process.

Current behavior

The dev server's only exit handler is inside the Ink TUI's useInput hook (packages/cli/src/screens/dev-screen.tsx:230-241):

useInput(
  (input, key) => {
    if (input === 'q' || (key.ctrl && input === 'c')) {
      if (watcherRef.current) {
        watcherRef.current.close()
      }
      exit()
      process.exit(0)
    }
  },
  { isActive: isTTY }
)

The dev command is registered with exit: 'manual' mode (packages/cli/src/commands/dev.ts), meaning the Kidd CLI framework expects the screen to handle its own exit. However, there is no process.on('SIGINT', ...) handler registered anywhere in the codebase.

When Ctrl+C is pressed:

1. First press — The SIGINT signal is consumed by Ink's default handler, which begins a graceful unmount but does not terminate the process (manual exit mode). The useInput handler doesn't fire because the signal is intercepted at a lower level.
2. Second press — Node's default SIGINT behavior force-terminates the process.

Expected behavior

A single Ctrl+C should gracefully shut down the dev server, close the file watcher, and exit the process.

Location

• packages/cli/src/commands/dev.ts — dev command registration with exit: 'manual'
• packages/cli/src/screens/dev-screen.tsx:230-241 — useInput exit handler (only TUI-level)
• packages/cli/src/lib/watcher.ts:171-179 — watcher cleanup (close + cancel debounced syncs)
• packages/cli/src/lib/rspress.ts:77-178 — Rspress dev server start/stop (no SIGINT handler)

Proposed approach

Register a process-level SIGINT handler that invokes the existing cleanup logic — close the file watcher, shut down the Rspress HTTP server, then process.exit(0). The cleanup code already exists; it just needs to be wired up to the signal.