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/devices/src/index.ts

@@ -0,0 +1,33 @@
+// Device-agnostic adapter interfaces.
+//
+// Business logic talks ONLY to these interfaces, never to a device SDK. Swapping
+// hardware means writing a new adapter that implements one of these — nothing
+// else changes. See wiki/concepts/device-adapter-pattern.md.
+//
+// SAFETY: a barrier is NOT a door. The relay interface expresses INTENT only
+// (`pulseOpen`); it never times or forces a close against a vehicle. Physical
+// safety (induction loops, anti-crush, auto-reverse) lives in the barrier
+// operator's own firmware. See wiki/concepts/barrier-not-a-door.md.
+
+export interface CardReaderDevice {
+  connect(): Promise<void>;
+  onCardRead(cb: (cardNumber: string, door: number) => void): void;
+  disconnect(): Promise<void>;
+}
+
+export interface TicketData {
+  readonly ticketId: string;
+  readonly lane: number;
+  readonly issuedAt: string; // ISO-8601
+}
+
+export interface PrinterDevice {
+  printTicket(data: TicketData): Promise<void>;
+  checkStatus(): Promise<"ready" | "offline" | "paper_out">;
+}
+
+export interface RelayDevice {
+  /** Express intent to open. NEVER timed/forced closed against a vehicle. */
+  pulseOpen(doorId: number): Promise<void>;
+  getDoorStatus(doorId: number): Promise<"open" | "closed">;
+}