Phase 1: chunk store, tile rendering pipeline, and Leaflet viewer

api: WS gateway with token auth (Postgres-backed servers table, seeded via
`bun run seed`), column-granularity chunk store (hand-written SQL
migrations, no drizzle-kit CLI — its config loader needs esbuild, which
doesn't install cleanly here), dirty-chunk Redis stream producer with
per-flush dedup, and a tile-serving route.

worker: consumes the dirty-chunk stream via a proper consumer group,
rasterizes each chunk's columns into a single-resolution top-down PNG
(static pre-Flattening block-id palette), uploads to MinIO, and upserts
the tile pointer.

frontend: barebones Leaflet 2D viewer (CRS.Simple, one native zoom level)
wired to /api/servers and /api/tiles.

Object storage: tiles live in a dedicated `mcmapper-tiles` bucket on the
existing shared MinIO instance (devstack-minio on octo-winsrv) instead of
a per-stack container, via a scoped access key limited to that one bucket
— see README's "Object storage" section. MINIO_SECRET_KEY is real and is
deliberately not committed; docker-compose layers an untracked .env over
.env.example for it.

Full pipeline verified end-to-end against live containers: WS auth ->
Postgres upsert -> deduped Redis dirty-chunk event -> worker rasterize ->
MinIO upload -> tile fetch through the api route, including from the
actual mod-side WS client (see MCMapper-Mod's matching commit).

frontend/src/views/index.pug

@@ -5,8 +5,19 @@ html(lang="en")
     meta(name="viewport" content="width=device-width, initial-scale=1")
     title MCMapper
     link(rel="stylesheet" href="/css/tailwind.css")
+    link(rel="stylesheet" href="https://unpkg.com/leaflet@1.9.4/dist/leaflet.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.
+    script(src="https://unpkg.com/leaflet@1.9.4/dist/leaflet.js")
+    style.
+      html, body, #map { height: 100%; margin: 0; }
+  body.bg-neutral-900.text-neutral-100
+    div#app.h-screen.flex.flex-col(x-data="mapmapper()" x-init="init()")
+      header.px-4.py-2.flex.items-center.gap-4.border-b.border-neutral-700
+        h1.text-lg.font-semibold MCMapper
+        span.text-sm.text-neutral-400(x-show="!loading && server")
+          | Viewing:
+          span(x-text="server?.name")
+        span.text-sm.text-neutral-500(x-show="loading") loading servers…
+        span.text-sm.text-red-400(x-show="!loading && !server") No server registered yet — see backend README (bun run seed).
+      div#map.flex-1
+    script(src="/js/map.js")