devices: pool-of-spaces model — drop lane, per-relay direction

A parking lot is one pool of spaces with a flexible set of entry/exit
points — no "lane". Direction is a property of each RELAY inside an access
controller; readers/cameras bind to a controller relay and inherit it.

Schema:
- drop `lane` from ledger_events, device_events, sessions
- rename lane_devices -> devices (no lane/direction columns)
- access config.relays=[{relay,direction,button?}]; reader/camera
  config.controllerId+relay binding
- fresh 0000_baseline migration (history reset; dev data was throwaway)

Signed ledger:
- remove `lane` from canonicalize(); bump signer keyId sw-hmac-v1 -> v2
  (v1 events won't verify under v2 — intentional, gated per-event by keyId)

Server:
- new device-resolve.ts (replaces lane-map.ts): relayForButton,
  relayForDevice, firstRelayByDirection, devicesByDirection
- entry-flow: button terminal -> its relay; exit/permit: reader's bound
  relay; dispatcher resolves the bound relay + inherited direction
- camera snapshots fire by direction site-wide, async, never block open
- DeviceConfig widened to nested JSON for relays[]

Web:
- wizard: no lane selector; add controllers (relay map + entry-button
  terminal) first, then bind readers/cameras/printers to a controller relay

Wiki: new entry-exit-points.md (replaces lane-direction); reworked
entry-exit-readers, parking-session, first-run-setup, device-registry,
append-only-event-chain, device-events; removed stale lane/LaneMap mentions.

apps/server/src/shift-service.ts

@@ -1,4 +1,4 @@
-import { eq, laneDevices, ledgerEvents, type Db } from "@parking/db";
+import { eq, devices, ledgerEvents, type Db } from "@parking/db";
 import { registry, type PrinterDevice } from "@parking/devices";
 import type { LedgerPayload } from "@parking/shared";
 import type { FastifyBaseLogger } from "fastify";
@@ -66,7 +66,6 @@ export class ShiftService {
     const startedAt = new Date().toISOString();
     await this.#log.append({
       type: "shift_open",
-      lane: -1,
       source: "manual",
       identity: operator, // the shift's operator; `identity` keys the shift to them
       payload: { operator },
@@ -105,7 +104,6 @@ export class ShiftService {
 
     await this.#log.append({
       type: "shift_z_report",
-      lane: -1,
       source: "manual",
       identity: operator,
       payload: {
@@ -163,9 +161,9 @@ export class ShiftService {
     }
   }
 
-  /** First enabled booth-receipt printer (any lane), or any enabled printer. */
+  /** First enabled booth-receipt printer, or any enabled printer. */
   async #boothPrinter(): Promise<PrinterDevice | null> {
-    const rows = await this.#db.select().from(laneDevices).where(eq(laneDevices.category, "printer")).all();
+    const rows = await this.#db.select().from(devices).where(eq(devices.category, "printer")).all();
     const enabled = rows.filter((r) => r.enabled);
     const booth = enabled.find((r) => (r.config as { role?: string }).role === "booth-receipt") ?? enabled[0];
     if (!booth) return null;