Initial scaffold: Turborepo monorepo + design wiki

Turborepo (pnpm workspaces) with all dependencies pinned to latest
mutually-compatible versions: turbo 2.9, TypeScript 6, Fastify 5,
React 19, Vite 8, better-sqlite3 12 + Drizzle ORM 0.45.

Layout:
- apps/server   Fastify backend (local JWT auth + role guard, /health)
- apps/web      React 19 + Vite 8 operator SPA
- packages/db   Drizzle schema on SQLite/WAL; append-only events + users
- packages/devices  reader/printer/relay adapter interfaces (intent-only relay)
- packages/shared   shared domain types

Architecture constraints from the design wiki are encoded in the scaffold:
append-only hash-chained + signed event log, device-agnostic adapters,
"a barrier is not a door" (relay expresses intent only), fully-local
offline-first auth.

wiki/ is an LLM-maintained Obsidian knowledge base (28 pages) ingested
from the architecture & design notes, with its own maintenance schema.

Verified: pnpm install, full turbo build (5/5), server boots and serves
/health, drizzle-kit generates the initial migration.

apps/web/src/App.tsx

@@ -0,0 +1,26 @@
+import { useEffect, useState } from "react";
+
+// Operator UI shell. Plain React (no admin framework) — the operator UI is
+// simple enough that a framework's abstractions cost more than they save.
+// See wiki/entities/react-vite-spa.md.
+
+export function App() {
+  const [health, setHealth] = useState<string>("checking…");
+
+  useEffect(() => {
+    fetch("/health")
+      .then((r) => r.json())
+      .then((d: { status: string }) => setHealth(d.status))
+      .catch(() => setHealth("unreachable"));
+  }, []);
+
+  return (
+    <main style={{ fontFamily: "system-ui", padding: "2rem" }}>
+      <h1>Parking System</h1>
+      <p>Operator console — scaffold.</p>
+      <p>
+        API health: <strong>{health}</strong>
+      </p>
+    </main>
+  );
+}

apps/web/src/main.tsx

@@ -0,0 +1,12 @@
+import { StrictMode } from "react";
+import { createRoot } from "react-dom/client";
+import { App } from "./App.js";
+
+const rootEl = document.getElementById("root");
+if (!rootEl) throw new Error("root element not found");
+
+createRoot(rootEl).render(
+  <StrictMode>
+    <App />
+  </StrictMode>,
+);

apps/web/src/vite-env.d.ts

@@ -0,0 +1 @@
+/// <reference types="vite/client" />