Restructure into pnpm monorepo with game shell, docs, and SpacetimeDB backend

- Restructure flat static prototype into pnpm workspace monorepo
- apps/game: playable shell with R3F 3D scene, HUD, SpacetimeDB connection
- apps/docs: design docs and prototypes
- apps/site: landing page
- packages/ui: shared Button and Panel primitives
- services/spacetimedb: backend module (9 tables, 11 reducers)
- Archive legacy static files to archive/legacy-static/
- Game loop: connect, undock, target, approach, dock, mine, sell
- Add pnpm-workspace.yaml, tsconfig.base.json, spacetime.json

apps/game/src/spacetime/useSpacetimeConnection.ts

@@ -0,0 +1,60 @@
+import { useEffect, useMemo, useState } from "react";
+import type { DbConnection } from "../module_bindings";
+import { createSpacetimeConnection, type ConnectionStatus, type IdentityLike } from "./client";
+
+const defaultUri = import.meta.env.VITE_SPACETIME_URI ?? import.meta.env.VITE_SPACETIMEDB_HOST ?? "http://localhost:3000";
+const defaultDatabase =
+  import.meta.env.VITE_SPACETIME_DATABASE ?? import.meta.env.VITE_SPACETIMEDB_DB_NAME ?? "void-nav-dev";
+
+export function useSpacetimeConnection(displayName: string) {
+  const [status, setStatus] = useState<ConnectionStatus>("idle");
+  const [message, setMessage] = useState<string>();
+  const [identity, setIdentity] = useState<IdentityLike>();
+  const [connection, setConnection] = useState<DbConnection | null>(null);
+  const [revision, setRevision] = useState(0);
+  const [reducerStatus, setReducerStatus] = useState<{ message: string; isError: boolean }>();
+
+  const config = useMemo(
+    () => ({
+      uri: defaultUri,
+      database: defaultDatabase,
+    }),
+    [],
+  );
+
+  useEffect(() => {
+    const conn = createSpacetimeConnection({
+      ...config,
+      displayName,
+      onStatus: (nextStatus, nextMessage) => {
+        setStatus(nextStatus);
+        setMessage(nextMessage);
+      },
+      onIdentity: setIdentity,
+      onDataChanged: () => setRevision((value) => value + 1),
+      onReducerStatus: (nextMessage, isError = false) => setReducerStatus({ message: nextMessage, isError }),
+    });
+
+    setConnection(conn);
+
+    const refresh = window.setInterval(() => {
+      if (conn) setRevision((value) => value + 1);
+    }, 1500);
+
+    return () => {
+      window.clearInterval(refresh);
+      conn?.disconnect?.();
+    };
+  }, [config, displayName]);
+
+  return {
+    connection,
+    status,
+    message,
+    identity,
+    revision,
+    reducerStatus,
+    uri: config.uri,
+    database: config.database,
+  };
+}