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.

.gitignore

@@ -0,0 +1,19 @@
+# env — never commit secrets
+.env
+
+# deps
+node_modules/
+
+# build output
+.next/
+dist/
+test-results/
+*.tsbuildinfo
+
+# agent tooling state
+.codenomad/
+
+# game state SQLite: lives on the host, volume-mounted into the container as
+# ./db → /app/db so it survives rebuilds — never tracked. Anchored to repo root:
+# an unanchored "db/" would also ignore lib/db/ (source).
+/db/