chore: replace lint-staged with nano-staged

[birtles]

Replace lint-staged with nano-staged 1.0.2, put the staged-file tasks in .nano-staged.json, and update the pre-commit hook and pnpm lockfile. Preserve the existing commands and matched file types.

Validation:

• Frozen offline dependency installation; formatting and git diff --check.
• Compared command coverage across tracked files and representative nested paths.
• Exercised the installed Husky hook in a disposable checkout: formats staged source, preserves unstaged edits, rejects invalid source, and restores the index and working file after failure.
• pnpm build and pnpm knip.