feat(berths): public berths API + health env-match endpoint

Adds the read-only public-website data feed promised by plan §4.5 and
§7.3. The marketing site's `getBerths()` swap is now a one-line URL
change against the existing 5-min TTL behaviour.

- src/app/api/public/berths/route.ts: GET / unauth, returns the full
  port-nimara berth list as { list, pageInfo } in the verbatim NocoDB
  shape ("Mooring Number", "Side Pontoon", quoted-key fields). Cache:
  s-maxage=300 + stale-while-revalidate=60. portSlug query param lets
  future ports opt in.
- src/app/api/public/berths/[mooringNumber]/route.ts: GET single. Up-
  front regex validation (^[A-Z]+\\d+$) rejects malformed lookups with
  400 + cache-control:no-store before hitting the DB. 404 + no-store
  when not found.
- src/app/api/public/health/route.ts: returns { status, env, appUrl,
  timestamp } so the marketing site can refuse to start when its
  CRM_PUBLIC_URL points at a different deployment env (§14.8 critical
  env-mismatch protection).
- src/lib/services/public-berths.ts: pure mapper with derivePublicStatus
  ("sold" wins; otherwise specific-interest junction OR
  status='under_offer' -> "Under Offer"; else "Available").
- 11 unit tests covering numeric coercion, status derivation,
  archived-berth handling, missing-map-data omission, and the
  status-precedence rule that "sold" trumps the specific-interest
  signal.

Smoke-tested: /api/public/berths -> 117 rows, A1 correctly shows
"Under Offer" (has interest_berths.is_specific_interest=true link),
INVALID -> 400, Z99 -> 404. Total tests: 996 -> 1007.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/lib/services/public-berths.ts

@@ -0,0 +1,131 @@
+/**
+ * Public-API berth shape + mapper.
+ *
+ * The public website's `/server/utils/berths.ts` previously read directly
+ * from the legacy NocoDB Berths table; after Phase 3 it calls the CRM
+ * `/api/public/berths` endpoint. The response shape must be a verbatim
+ * match for the NocoDB output so the website's Vue templates and
+ * `Berth` type don't need code changes (plan §7.3).
+ *
+ * Lives outside the route handler so vitest can exercise the mapping
+ * + status-derivation logic without spinning up a Next.js request.
+ */
+
+import type { Berth, BerthMapData } from '@/lib/db/schema/berths';
+
+export interface PublicMapData {
+  path: string;
+  x: string;
+  y: string;
+  transform: string;
+  fontSize: string;
+}
+
+/** NocoDB display strings - the public website's `Berth.Status` enum. */
+export type PublicStatus = 'Available' | 'Under Offer' | 'Sold';
+
+/**
+ * Verbatim NocoDB-style payload. Keys are quoted with capital-first
+ * spacing because the upstream consumer (the public website) iterates
+ * them by literal string key (e.g. `berth["Mooring Number"]`).
+ */
+export interface PublicBerth {
+  Id: string;
+  'Mooring Number': string;
+  Length: number | null;
+  Draft: number | null;
+  'Side Pontoon': string | null;
+  'Power Capacity': number | null;
+  Voltage: number | null;
+  Status: PublicStatus;
+  Width: number | null;
+  Area: string | null;
+  'Mooring Type': string | null;
+  'Bow Facing': string | null;
+  'Cleat Type': string | null;
+  'Cleat Capacity': string | null;
+  'Bollard Type': string | null;
+  'Bollard Capacity': string | null;
+  'Nominal Boat Size': number | null;
+  Access: string | null;
+  'Map Data'?: PublicMapData;
+}
+
+// ─── Helpers ────────────────────────────────────────────────────────────────
+
+function toNumber(value: unknown): number | null {
+  if (value === null || value === undefined || value === '') return null;
+  const n = typeof value === 'number' ? value : parseFloat(String(value));
+  return Number.isFinite(n) ? n : null;
+}
+
+function toString(value: unknown): string | null {
+  if (value === null || value === undefined) return null;
+  if (typeof value === 'string') return value;
+  if (typeof value === 'number') return String(value);
+  return null;
+}
+
+/**
+ * Derive the public-facing status string from the CRM's internal status
+ * + the per-berth `is_specific_interest` flag. Per plan §1:
+ *
+ *   Public "Under Offer" = berth.status = 'sold'? No - that's "Sold".
+ *                         berth.status = 'under_offer' OR
+ *                         at least one interest_berths row marked
+ *                         is_specific_interest = true ON an active
+ *                         (non-archived) interest.
+ */
+export function derivePublicStatus(
+  internalStatus: string,
+  hasSpecificInterest: boolean,
+): PublicStatus {
+  if (internalStatus === 'sold') return 'Sold';
+  if (internalStatus === 'under_offer' || hasSpecificInterest) return 'Under Offer';
+  return 'Available';
+}
+
+function mapMapData(row: BerthMapData | null | undefined): PublicMapData | undefined {
+  if (!row) return undefined;
+  return {
+    path: row.svgPath ?? '',
+    x: row.x === null || row.x === undefined ? '' : String(row.x),
+    y: row.y === null || row.y === undefined ? '' : String(row.y),
+    transform: row.transform ?? '',
+    fontSize: row.fontSize === null || row.fontSize === undefined ? '' : String(row.fontSize),
+  };
+}
+
+/**
+ * Map a single CRM berth row + its (optional) map_data + a flag about
+ * whether the berth has an active specific-interest link, into the
+ * public response shape. The flag is computed once for a batch by the
+ * route handler; this function is pure.
+ */
+export function toPublicBerth(
+  berth: Berth,
+  mapData: BerthMapData | null | undefined,
+  hasSpecificInterest: boolean,
+): PublicBerth {
+  return {
+    Id: berth.id,
+    'Mooring Number': berth.mooringNumber,
+    Length: toNumber(berth.lengthFt),
+    Draft: toNumber(berth.draftFt),
+    Width: toNumber(berth.widthFt),
+    'Side Pontoon': toString(berth.sidePontoon),
+    'Power Capacity': toNumber(berth.powerCapacity),
+    Voltage: toNumber(berth.voltage),
+    Status: derivePublicStatus(berth.status, hasSpecificInterest),
+    Area: toString(berth.area),
+    'Mooring Type': toString(berth.mooringType),
+    'Bow Facing': toString(berth.bowFacing),
+    'Cleat Type': toString(berth.cleatType),
+    'Cleat Capacity': toString(berth.cleatCapacity),
+    'Bollard Type': toString(berth.bollardType),
+    'Bollard Capacity': toString(berth.bollardCapacity),
+    'Nominal Boat Size': toNumber(berth.nominalBoatSize),
+    Access: toString(berth.access),
+    ...(mapMapData(mapData) ? { 'Map Data': mapMapData(mapData)! } : {}),
+  };
+}