infra: base stack config (Next 16 + React 19 + TS strict, Tailwind v4, sql.js/Drizzle deps)

Copied/adapted from Flight-Ops (../flight): tsconfig/next/vitest configs verbatim,
Dockerfile two-stage node:22-slim with node_modules in build context (zero outbound
network at image-build time), .dockerignore/.gitignore adapted. package.json renamed
to space-wanderer v0.1.0; dropped maplibre-gl + assets:download; added Tailwind v4,
Radix slot, cva/clsx/tailwind-merge for the scificn-ui component layer.

vitest.config.ts

@@ -0,0 +1,12 @@
+import { defineConfig } from 'vitest/config';
+import path from 'node:path';
+
+export default defineConfig({
+  resolve: {
+    alias: { '@': path.resolve(process.cwd()) },
+  },
+  test: {
+    environment: 'node',
+    include: ['**/*.test.ts'],
+  },
+});