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).

api/scripts/seed-server.ts

@@ -0,0 +1,30 @@
+import { db } from "../src/db/client";
+import { servers } from "../src/db/schema";
+import { sql } from "../src/db/client";
+
+// Phase 6 will add a real admin registration API/UI. Until then, Phase 1 needs at least one
+// server row to hand a token to the mod — run with MCMAPPER_SEED_SERVER_NAME/_TOKEN set.
+async function main() {
+  const name = process.env.MCMAPPER_SEED_SERVER_NAME;
+  const token = process.env.MCMAPPER_SEED_SERVER_TOKEN;
+  const authMode = process.env.MCMAPPER_SEED_SERVER_AUTH_MODE ?? "offline";
+
+  if (!name || !token) {
+    console.error("[seed] set MCMAPPER_SEED_SERVER_NAME and MCMAPPER_SEED_SERVER_TOKEN");
+    process.exit(1);
+  }
+
+  const [row] = await db
+    .insert(servers)
+    .values({ name, token, authMode })
+    .onConflictDoUpdate({ target: servers.token, set: { name, authMode } })
+    .returning();
+
+  console.log(`[seed] server ready: id=${row.id} name=${row.name}`);
+  await sql.end();
+}
+
+main().catch((err) => {
+  console.error("[seed] failed:", err);
+  process.exit(1);
+});