chore: add granular check:fmt / check:lint scripts at root

`vp check` bundles format, lint, and typecheck, which hides which concern
failed and offers no way to run a single slice. Add explicit per-concern
entry points at the workspace root:

  check       -> vp check            (umbrella, unchanged behavior)
  check:fmt   -> vp fmt --check      (format only)
  check:lint  -> vp lint             (lint + typecheck)

No separate check:type: with typeAware/typeCheck enabled in the root config,
vp lint already runs the tsc typecheck, so check:lint covers it.

package.json

@@ -5,6 +5,9 @@
   "description": "Vue 3 terminal UI framework. Build AI agent interfaces and TUI apps with Yoga flexbox.",
   "type": "module",
   "scripts": {
+    "check": "vp check",
+    "check:fmt": "vp fmt --check",
+    "check:lint": "vp lint",
     "ready": "vp check && vp run -r test && vp run -r build && cd packages/runtime-tests && pnpm typecheck:fixtures && pnpm pty-test",
     "dev": "vp run website#dev",
     "prepare": "vp config"