Add Next.js 15 app skeleton with Tailwind v4 and shadcn/ui

Next.js 15 + React 19, Tailwind v4, shadcn/ui (button, card, input,
dialog), postcss config, standalone output. ESLint extended with
next/core-web-vitals via eslint-config-next flat export. node-linker=hoisted
in .npmrc to allow standalone builds on Windows (symlink restriction).
next-env.d.ts added to .gitignore.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

components.json

@@ -0,0 +1,25 @@
+{
+  "$schema": "https://ui.shadcn.com/schema.json",
+  "style": "base-nova",
+  "rsc": true,
+  "tsx": true,
+  "tailwind": {
+    "config": "",
+    "css": "src/app/globals.css",
+    "baseColor": "neutral",
+    "cssVariables": true,
+    "prefix": ""
+  },
+  "iconLibrary": "lucide",
+  "rtl": false,
+  "aliases": {
+    "components": "@/components",
+    "utils": "@/lib/utils",
+    "ui": "@/components/ui",
+    "lib": "@/lib",
+    "hooks": "@/hooks"
+  },
+  "menuColor": "default",
+  "menuAccent": "subtle",
+  "registries": {}
+}