Add vue3-vite scaffold: skill, script, shell wrapper, and prompt

- resources/skills/vue3-vite/SKILL.md: procedure, outputs, and atomic design conventions
- resources/scripts/scaffold-vue3-vite.mjs: self-contained scaffold generating package.json, vite.config.js, index.html, router, pages, atomic component dirs, and SCSS foundations
- resources/scripts/scaffold-vue3-vite.sh: Node.js-delegating shell wrapper
- resources/prompts/scaffold-vue3-vite.prompt.md: chat-invocable prompt following shared pattern

resources/prompts/scaffold-vue3-vite.prompt.md

@@ -0,0 +1,18 @@
+---
+name: "scaffold-vue3-vite"
+description: "Scaffold a new Vue 3 + Vite project with vue-router, atomic component directories, and SCSS styling foundations."
+agent: "agent"
+tools: [read, search, execute]
+argument-hint: "project-root=<path> app-name=<name> mode=<dry-run|apply> port=<dev-server-port>"
+---
+
+Scaffold a new Vue 3 + Vite project using the shared scaffold script.
+
+Requirements:
+
+- Prefer `resources/scripts/scaffold-vue3-vite.sh` over manually creating files.
+- Default to `--mode dry-run` unless the user explicitly asks for apply mode.
+- Resolve `--project-root` and `--app-name` before running; ask if missing.
+- After `--mode apply` completes, instruct the user to run `npm install` then
+  `npm run dev` to verify the dev server starts cleanly.
+- Summarize the files created and the next steps.