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/device-resolve.ts

@@ -0,0 +1,155 @@
+import { and, eq, devices, type Db, type DeviceRow } from "@parking/db";
+
+// Device resolution for the pool-of-spaces model — NO lane. A parking lot is one
+// pool with a flexible set of entry/exit points. Direction lives on each RELAY
+// inside an access controller, and readers/cameras BIND to a (controller, relay).
+// See wiki/concepts/entry-exit-points.md.
+
+/** A flow direction. "both" = one relay/barrier serving entry AND exit. */
+export type Direction = "entry" | "exit" | "both";
+/** A concrete flow a credential/button drives (never "both"). */
+export type FlowDirection = "entry" | "exit";
+
+/** One relay on an access controller: which barrier it opens, in which direction,
+ *  and (optionally) the input terminal its entry button is wired to. */
+export interface RelaySpec {
+  /** 1-based relay channel on the board (the driver's pulseOpen(doorId)). */
+  readonly relay: number;
+  readonly direction: Direction;
+  /** 1-based input terminal of the entry button that fires this relay (transient
+   *  entry). Absent = no button at this barrier (subscriber/reader-driven only). */
+  readonly button?: number;
+}
+
+/** Access controller config (the `relays[]` map + connection fields). */
+interface AccessConfig {
+  readonly relays?: RelaySpec[];
+  readonly [k: string]: unknown;
+}
+
+/** Reader/camera config: optional binding to a controller relay. */
+interface BoundConfig {
+  /** The access `devices.id` this reader/camera sits at. */
+  readonly controllerId?: string;
+  /** The relay on that controller it opens. */
+  readonly relay?: number;
+  /** Fallback direction when not bound to a relay. */
+  readonly direction?: Direction;
+  readonly [k: string]: unknown;
+}
+
+/** A resolved barrier: the controller row + the specific relay to pulse. */
+export interface ResolvedRelay {
+  readonly controller: DeviceRow;
+  readonly relay: number;
+  readonly direction: Direction;
+}
+
+/** All enabled access controller rows. */
+function accessRows(db: Db): DeviceRow[] {
+  return db
+    .select()
+    .from(devices)
+    .where(eq(devices.category, "access"))
+    .all()
+    .filter((r) => r.enabled);
+}
+
+/** The relay specs declared on an access controller (defaults to none). */
+export function relaysOf(row: DeviceRow): RelaySpec[] {
+  const cfg = row.config as AccessConfig;
+  return Array.isArray(cfg.relays) ? cfg.relays : [];
+}
+
+/**
+ * Resolve a button press to the relay it fires: the access controller with this
+ * deviceId, and the relay whose `button` terminal matches the pressed input. Only
+ * an ENTRY (or both) relay is a transient-entry trigger. Returns null otherwise.
+ */
+export function relayForButton(db: Db, controllerId: string, terminal: number): ResolvedRelay | null {
+  const row = db
+    .select()
+    .from(devices)
+    .where(and(eq(devices.id, controllerId), eq(devices.category, "access")))
+    .get();
+  if (!row || !row.enabled) return null;
+  const spec = relaysOf(row).find((r) => r.button === terminal);
+  if (!spec) return null;
+  if (spec.direction !== "entry" && spec.direction !== "both") return null;
+  return { controller: row, relay: spec.relay, direction: spec.direction };
+}
+
+/**
+ * Resolve a reader/camera to the relay it opens. Preferred: its config binding
+ * (controllerId + relay) → exactly that barrier, direction inherited from the relay
+ * spec. Fallback (unbound): the device's config.direction + the first relay site-
+ * wide matching that direction — keeps the single-barrier case trivial. Null if
+ * nothing resolves (no barrier to open).
+ */
+export function relayForDevice(db: Db, deviceRow: DeviceRow): ResolvedRelay | null {
+  const cfg = deviceRow.config as BoundConfig;
+
+  // Bound: follow controllerId + relay to the exact barrier.
+  if (cfg.controllerId && typeof cfg.relay === "number") {
+    const controller = db
+      .select()
+      .from(devices)
+      .where(and(eq(devices.id, cfg.controllerId), eq(devices.category, "access")))
+      .get();
+    if (controller && controller.enabled) {
+      const spec = relaysOf(controller).find((r) => r.relay === cfg.relay);
+      if (spec) return { controller, relay: spec.relay, direction: spec.direction };
+    }
+    return null;
+  }
+
+  // Unbound: fall back to the device's declared direction + first matching relay.
+  const want = cfg.direction;
+  if (want === "entry" || want === "exit" || want === "both") {
+    return firstRelayByDirection(db, want === "both" ? "entry" : want);
+  }
+  return null;
+}
+
+/**
+ * The first relay site-wide serving a direction ("both" relays match either).
+ * Used as the unbound fallback and where a flow only needs "an exit barrier".
+ */
+export function firstRelayByDirection(db: Db, direction: FlowDirection): ResolvedRelay | null {
+  for (const controller of accessRows(db)) {
+    const spec = relaysOf(controller).find(
+      (r) => r.direction === direction || r.direction === "both",
+    );
+    if (spec) return { controller, relay: spec.relay, direction: spec.direction };
+  }
+  return null;
+}
+
+/** Enabled devices of a category whose direction matches `want` (or is "both").
+ *  Direction is inherited from each device's bound relay, else its config fallback.
+ *  Used for snapshots: every entry/exit camera fires on an entry/exit. */
+export function devicesByDirection(
+  db: Db,
+  category: DeviceRow["category"],
+  want: FlowDirection,
+): DeviceRow[] {
+  return db
+    .select()
+    .from(devices)
+    .where(eq(devices.category, category))
+    .all()
+    .filter((r) => {
+      if (!r.enabled) return false;
+      const d = directionOf(db, r);
+      return d === want || d === "both";
+    });
+}
+
+/** The direction a reader/camera operates in (inherited from its bound relay, or
+ *  its config fallback). "both" when undetermined → the flow infers. */
+export function directionOf(db: Db, deviceRow: DeviceRow): Direction {
+  const resolved = relayForDevice(db, deviceRow);
+  if (resolved) return resolved.direction;
+  const cfg = deviceRow.config as BoundConfig;
+  return cfg.direction === "entry" || cfg.direction === "exit" ? cfg.direction : "both";
+}