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.

wiki/concepts/entry-exit-readers.md

@@ -0,0 +1,40 @@
+---
+type: concept
+tags: [parking, architecture, readers]
+sources: [parking-system-architecture]
+updated: 2026-06-14
+---
+
+# Entry / Exit Readers
+
+There are **two populations** of users, and they map to **two integration paths**. (See
+[[parking-system-architecture]] §8.)
+
+- **Permit holders / subscribers** — want hands-free/quick entry. Best served by reads reaching
+  the **controller directly** ([[wiegand]]) so it can decide autonomously (works if host is down).
+- **Casual / transient** — printed ticket, pay-on-exit, or plate recognition. Inherently
+  **host-side** identity sources ([[lpr-camera]], QR/ticket scanner).
+
+## How reads reach the system
+
+| Reader type | Who sees the read | Decision by | Offline autonomy |
+| --- | --- | --- | --- |
+| [[wiegand]] reader → UHPPOTE port | The controller | Controller (onboard card list) | **Yes** — works if host down |
+| Pure TCP/IP reader | Host only | Host, then UDP `open` to relay | No — host on critical path |
+| [[lpr-camera|LPR]] / QR scanner | Host only | Host | No |
+
+## Key points
+
+- **Pure network readers are invisible to the [[uhppote-controller]]** — it only generates events
+  for its own terminals. For a pure-TCP reader, only the host can listen/decide/command; the
+  controller is demoted to a commanded relay (onboard card DB + offline autonomy bypassed).
+- **Check for a Wiegand output first** — many "network" readers have both; wiring Wiegand in
+  keeps autonomy + native event log.
+- **Both models can share one relay** (valid Wiegand read **or** host `open` in "controlled"
+  mode), so one lane serves permit + casual.
+- **Host-in-the-loop is good for fraud detection** — two independent records (host's signed
+  [[append-only-event-chain]] entry + the UHPPOTE remote-open event) should reconcile 1:1; any
+  mismatch is an anomaly.
+
+Autonomy caveat: with remote-host control enabled, the controller expects host comms every ~30 s
+or reverts to local control (Wiegand-on-board lanes only).