Phase 1 scaffold: auth for all apps

- Backend: Fastify with two listeners (public + internal), routes, services, DB migration + seed
- client_app: Flutter with BLoC, all auth screens (welcome, display name, register, OTP, force-register)
- mitra_app: Flutter with BLoC, OTP-only login
- control_center: React + Vite, email/password login, mitra/user management, anonymity settings
- Docs: phase1 plan, API contract, client app mockup
- CLAUDE.md and shared memory for all subprojects

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/src/app.internal.js

@@ -0,0 +1,23 @@
+import Fastify from 'fastify'
+import sensible from '@fastify/sensible'
+import { mitraManagementRoutes } from './routes/internal/mitra.routes.js'
+import { ccUserRoutes } from './routes/internal/cc-user.routes.js'
+import { rolesRoutes } from './routes/internal/roles.routes.js'
+import { internalAuthRoutes } from './routes/internal/auth.routes.js'
+import { internalConfigRoutes } from './routes/internal/config.routes.js'
+import { errorHandler } from './plugins/error-handler.js'
+
+export const buildInternalApp = async () => {
+  const app = Fastify({ logger: true })
+
+  await app.register(sensible)
+  app.setErrorHandler(errorHandler)
+
+  app.register(internalAuthRoutes, { prefix: '/internal/auth' })
+  app.register(mitraManagementRoutes, { prefix: '/internal/mitras' })
+  app.register(ccUserRoutes, { prefix: '/internal/control-center-users' })
+  app.register(rolesRoutes, { prefix: '/internal/roles' })
+  app.register(internalConfigRoutes, { prefix: '/internal/config' })
+
+  return app
+}