feat(modules): venue-module registry — entitled ∩ activated, requireModule, Setup panel

Groundwork for the Car Wash pilot (wiki/decisions/venue-modules.md, build-order
steps 1 + 3). No Car Wash code yet; validation is the first module behind the
seam, unchanged in behaviour.

- @parking/shared: MODULE_IDS, ModuleManifest, MODULES (parking required;
  validation dependsOn parking), parseEntitledModules / resolveModuleActivation
  / effectiveModules as pure functions.
- DB: site_config.modules_json (migration 0026, hand-written + journal;
  additive, nullable = everything entitled).
- Server: modules.ts (entitledModules from MODULES_ENTITLED env, activated
  from site_config, effective set, requireModule preHandler → 403
  module_disabled); modules/index.ts registers folder-based modules by
  iterating the registry (modules/validation); site-config GET exposes
  modules/modulesEntitled/modulesActivated, PUT takes the full desired set,
  enforces entitlement + dependency rules (400 with reason) and signs one
  config_change per module that actually flips; /api/auth/me carries the
  effective set; validation routes guarded requireModule → requirePermission.
- Web: lib/modules.ts + modules/{index,validation}; router.tsx spreads
  WEB_MODULES into nav + route tree (validate route no longer named there);
  Setup → Site "Modules" panel (required shown disabled, dependencies as
  hints, server refusal shown verbatim); validation sections + programs fetch
  gated on the module; App invalidates the router whenever the session
  changes (route-context consumers only re-read on navigation — the nav was
  stale after a flip, and after every other setUser too).
- Lavazh validation station retired (STATIONS = ["bar"]; rows untouched).
- Deploy: MODULES_ENTITLED=parking,validation explicit in both booth stacks;
  documented in .env.example.
- Tests: modules.test.ts (7); suite 329/329; web build clean; Playwright
  round-trip on /setup/site verified live.

Claude-Session: https://claude.ai/code/session_01FWncR69HgGPuei1dLrW3cU

apps/server/src/routes/validations.ts

@@ -12,6 +12,7 @@ import {
 } from "@parking/db";
 import { VALIDATION_MODES, type ValidationMode } from "@parking/shared";
 import { requirePermission } from "../auth.js";
+import { requireModule } from "../modules.js";
 import type { EventLog } from "../event-log.js";
 import { liveValidations, sessionValidations } from "../validations.js";
 
@@ -75,9 +76,12 @@ function validateProgram(b: ProgramBody): string | null {
 }
 
 export async function validationRoutes(app: FastifyInstance, db: Db, eventLog: EventLog): Promise<void> {
-  const siteRead = requirePermission("site:read");
-  const siteWrite = requirePermission("site:update");
-  const applyGuard = requirePermission("validation:create");
+  // Every route is behind the venue-module gate FIRST (403 module_disabled when the
+  // site has validation off — see ../modules.ts), then the usual permission guard.
+  const moduleOn = requireModule(db, "validation");
+  const siteRead = [moduleOn, requirePermission("site:read")];
+  const siteWrite = [moduleOn, requirePermission("site:update")];
+  const applyGuard = [moduleOn, requirePermission("validation:create")];
 
   const liveProgram = (id: string) =>
     db