Add bun integration tests for docs flow, update integration guide

- Add test/integration.test.ts: getServicePublicKey, full flow (register, login, createCollection, createPointFeature, listFeatures)
- Update docs example: registerBySigningServiceKey then loginWithSignature
- Document integration tests in typescript-frontend-integration.md

Made-with: Cursor

internal/app/service.go

@@ -15,7 +15,7 @@ var (
 	ErrUnauthorized              = errors.New("unauthorized")
 	ErrForbidden                 = errors.New("forbidden")
 	ErrBadRequest                = errors.New("bad request")
-	ErrRegistrationNotConfigured = errors.New("registration by signature not configured; set ADMIN_PUBLIC_KEY")
+	ErrRegistrationNotConfigured = errors.New("registration by signature not configured")
 	ErrInviteInvalid             = errors.New("invite invalid")
 	ErrInviteExpired             = errors.New("invite expired")
 	ErrInviteExhaust             = errors.New("invite exhausted")
@@ -30,13 +30,13 @@ type Config struct {
 }
 
 type Service struct {
-	store            *store.MemoryStore
+	store            store.Store
 	config           Config
 	servicePublicKey string
 }
 
-func NewService(memoryStore *store.MemoryStore, cfg Config, servicePublicKey string) *Service {
-	return &Service{store: memoryStore, config: cfg, servicePublicKey: servicePublicKey}
+func NewService(st store.Store, cfg Config, servicePublicKey string) *Service {
+	return &Service{store: st, config: cfg, servicePublicKey: servicePublicKey}
 }
 
 type InvitationPayload struct {