Re-delegate elicited app targets through full CLI resolution

Follow-up to #2031, from Codex review round 7. When a bare app command at a root is retargeted by target elicitation (defaultPackage, picker, auto-select), the binding swaps the spawn cwd and PWD for the tool, but the executing local CLI, its Node runtime, and PATH were already resolved for the invocation directory.

Within one workspace this matches the supported single-Vite+-version model and the behavior is correct. The gap is the non-workspace framework shape: a root whose vite.config.ts points defaultPackage at a directory that carries its own vite-plus install or runtime pin (.node-version, devEngines.runtime). There, `cd && vp build` resolves that local install and runtime, while `vp build` at the root elicits inside the CLI chosen at the root (possibly the global bundled one), so versions can skew.

Candidate fix: when elicitation returns a target directory, re-delegate as if the user had run `vp -C ` from the top: the global binary re-runs local-CLI and runtime resolution from the target before dispatching (needs a signal across the NAPI boundary, or the global CLI performing elicitation for the bare-at-root case before choosing the local CLI). The RFC documents the current scoping in the equivalence section.

RFC の equivalence セクションを読み、その後、`vp -C ` に対して使用される target elicitation とローカル CLI/runtime の解決を追跡します。vite.config.ts で defaultPackage を設定している root に対する `cd && vp build` と比較します。完了条件は、elicitation された target が dispatch 前に自身のローカル CLI、Node runtime、PATH を再解決することです。

索引モデルが issue の本文から書いたものです。