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.

packages/db/src/index.ts

@@ -0,0 +1,19 @@
+import Database from "better-sqlite3";
+import { drizzle } from "drizzle-orm/better-sqlite3";
+import * as schema from "./schema.js";
+
+export * from "./schema.js";
+
+/**
+ * Open the local SQLite database in WAL mode. WAL allows many concurrent readers
+ * plus one writer — a parking workload never approaches SQLite's single-writer
+ * limit. See wiki/entities/sqlite.md.
+ */
+export function createDb(url = process.env.DATABASE_URL ?? "./parking.sqlite") {
+  const sqlite = new Database(url);
+  sqlite.pragma("journal_mode = WAL");
+  sqlite.pragma("foreign_keys = ON");
+  return drizzle(sqlite, { schema });
+}
+
+export type Db = ReturnType<typeof createDb>;