Phase 0: scaffold three-service backend (api/worker/frontend)

api/ (ElysiaJS+Bun WS gateway skeleton), worker/ (Rust, Redis dirty-chunk
stream consumer behind a swappable RenderBackend trait), frontend/
(ElysiaJS+Pug+Tailwind4+Alpine, one server-rendered page) — all three
verified running locally. docker-compose wires them up with postgres,
redis, minio (rendered tile/mesh object storage), and Caddy as reverse
proxy.

frontend/src/views/index.pug

@@ -0,0 +1,12 @@
+doctype html
+html(lang="en")
+  head
+    meta(charset="utf-8")
+    meta(name="viewport" content="width=device-width, initial-scale=1")
+    title MCMapper
+    link(rel="stylesheet" href="/css/tailwind.css")
+    script(defer src="https://unpkg.com/alpinejs@3.x.x/dist/cdn.min.js")
+  body.bg-neutral-900.text-neutral-100.min-h-screen.flex.items-center.justify-center
+    div(x-data="{ ready: true }")
+      h1.text-2xl.font-semibold MCMapper
+      p.text-neutral-400(x-show="ready") Backend scaffold is up. Map viewer lands in Phase 1.