feat: build core API, fraud engine, notifier, and frontend

Phase 1 — Core API (Go):
- Events, guests, tokens, RSVPs CRUD on PostgreSQL via pgx/v5
- HMAC-signed per-guest tokens with format validation
- Health endpoint with DB ping, slog JSON logging, graceful shutdown

Phase 2 — NATS + Fraud Engine:
- NATS JetStream pub/sub with explicit-ack consumers
- Python/FastAPI fraud engine with heuristic risk scoring
  (fingerprint mismatch, IP change, missing signals, repeated access)
- gRPC sync scoring with 250ms fail-open timeout
- Per-guest baseline tracking; risk bands low/medium/high/block

Phase 3 — Notifications + Frontend:
- Notification worker scaffolding (Twilio/SES stubs, retry/backoff)
- Nuxt 3 frontend with Tailwind dark theme + brand green
- Live monitor via WebSocket with auto-reconnect
- Activity history endpoint backfills monitor with RSVPs +
  scored access checks (including blocked attempts)

UX polish:
- Marketing-friendly landing page (hero mockup, how-it-works,
  features, use cases, testimonials, FAQ, final CTA)
- Animated layered card mockups on landing + new-event page
- Plus-ones stepper, RSVP status badges, filter buttons
- Friendly access-check labels (Verified/Review/Suspicious/Blocked)
- Dashboard hydration fix via ClientOnly wrapper

Infrastructure:
- docker-compose for full local dev (postgres, nats, api,
  fraud-engine, notifier, frontend)
- Multi-stage Dockerfiles, non-root UID 1000
- Integration tests with testcontainers-go

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/domain/event.go

@@ -0,0 +1,44 @@
+package domain
+
+import (
+	"errors"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type EventStatus string
+
+const (
+	EventStatusDraft     EventStatus = "draft"
+	EventStatusPublished EventStatus = "published"
+	EventStatusClosed    EventStatus = "closed"
+	EventStatusArchived  EventStatus = "archived"
+)
+
+func (s EventStatus) Valid() bool {
+	switch s {
+	case EventStatusDraft, EventStatusPublished, EventStatusClosed, EventStatusArchived:
+		return true
+	}
+	return false
+}
+
+type Event struct {
+	ID          uuid.UUID      `json:"id"`
+	HostID      uuid.UUID      `json:"host_id"`
+	Name        string         `json:"name"`
+	Slug        string         `json:"slug"`
+	EventDate   time.Time      `json:"event_date"`
+	Venue       string         `json:"venue"`
+	MaxCapacity int            `json:"max_capacity"`
+	Settings    map[string]any `json:"settings"`
+	Status      EventStatus    `json:"status"`
+	CreatedAt   time.Time      `json:"created_at"`
+	UpdatedAt   time.Time      `json:"updated_at"`
+}
+
+var (
+	ErrEventNotFound = errors.New("event not found")
+	ErrSlugTaken     = errors.New("slug already in use")
+)

internal/domain/event_test.go

@@ -0,0 +1,25 @@
+package domain
+
+import "testing"
+
+func TestEventStatus_Valid(t *testing.T) {
+	tests := []struct {
+		name string
+		in   EventStatus
+		want bool
+	}{
+		{"draft", EventStatusDraft, true},
+		{"published", EventStatusPublished, true},
+		{"closed", EventStatusClosed, true},
+		{"archived", EventStatusArchived, true},
+		{"empty", "", false},
+		{"unknown", "running", false},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := tt.in.Valid(); got != tt.want {
+				t.Errorf("Valid() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}

internal/domain/guest.go

@@ -0,0 +1,22 @@
+package domain
+
+import (
+	"errors"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type Guest struct {
+	ID           uuid.UUID `json:"id"`
+	EventID      uuid.UUID `json:"event_id"`
+	Name         string    `json:"name"`
+	Email        *string   `json:"email,omitempty"`
+	Phone        *string   `json:"phone,omitempty"`
+	PlusOnes     int       `json:"plus_ones"`
+	DietaryNotes *string   `json:"dietary_notes,omitempty"`
+	TableNumber  *int      `json:"table_number,omitempty"`
+	CreatedAt    time.Time `json:"created_at"`
+}
+
+var ErrGuestNotFound = errors.New("guest not found")

internal/domain/rsvp.go

@@ -0,0 +1,41 @@
+package domain
+
+import (
+	"errors"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type RSVPResponse string
+
+const (
+	RSVPAttending RSVPResponse = "attending"
+	RSVPDeclined  RSVPResponse = "declined"
+	RSVPMaybe     RSVPResponse = "maybe"
+)
+
+func (r RSVPResponse) Valid() bool {
+	switch r {
+	case RSVPAttending, RSVPDeclined, RSVPMaybe:
+		return true
+	}
+	return false
+}
+
+type RSVP struct {
+	ID                uuid.UUID      `json:"id"`
+	GuestID           uuid.UUID      `json:"guest_id"`
+	Response          RSVPResponse   `json:"response"`
+	PlusOnes          int            `json:"plus_ones"`
+	DietaryNotes      *string        `json:"dietary_notes,omitempty"`
+	SubmittedAt       time.Time      `json:"submitted_at"`
+	DeviceFingerprint map[string]any `json:"device_fingerprint,omitempty"`
+	IPAddress         *string        `json:"ip_address,omitempty"`
+	RiskScore         *int           `json:"risk_score,omitempty"`
+}
+
+var (
+	ErrRSVPAlreadySubmitted = errors.New("rsvp already submitted")
+	ErrRSVPBlocked          = errors.New("rsvp blocked due to fraud risk")
+)

internal/domain/token.go

@@ -0,0 +1,49 @@
+package domain
+
+import (
+	"errors"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type TokenStatus string
+
+const (
+	TokenStatusActive  TokenStatus = "active"
+	TokenStatusUsed    TokenStatus = "used"
+	TokenStatusRevoked TokenStatus = "revoked"
+	TokenStatusExpired TokenStatus = "expired"
+)
+
+type Token struct {
+	ID        uuid.UUID   `json:"id"`
+	GuestID   uuid.UUID   `json:"guest_id"`
+	TokenHash string      `json:"-"`
+	ExpiresAt time.Time   `json:"expires_at"`
+	Status    TokenStatus `json:"status"`
+	UsedAt    *time.Time  `json:"used_at,omitempty"`
+	CreatedAt time.Time   `json:"created_at"`
+}
+
+func (t *Token) IsValid(now time.Time) error {
+	switch t.Status {
+	case TokenStatusUsed:
+		return ErrTokenAlreadyUsed
+	case TokenStatusRevoked:
+		return ErrTokenRevoked
+	case TokenStatusExpired:
+		return ErrTokenExpired
+	}
+	if now.After(t.ExpiresAt) {
+		return ErrTokenExpired
+	}
+	return nil
+}
+
+var (
+	ErrTokenNotFound    = errors.New("token not found")
+	ErrTokenExpired     = errors.New("token expired")
+	ErrTokenRevoked     = errors.New("token revoked")
+	ErrTokenAlreadyUsed = errors.New("token already used")
+)

internal/domain/user.go

@@ -0,0 +1,21 @@
+package domain
+
+import (
+	"errors"
+	"time"
+
+	"github.com/google/uuid"
+)
+
+type User struct {
+	ID        uuid.UUID `json:"id"`
+	Email     string    `json:"email"`
+	Name      string    `json:"name"`
+	CreatedAt time.Time `json:"created_at"`
+	UpdatedAt time.Time `json:"updated_at"`
+}
+
+var (
+	ErrUserNotFound  = errors.New("user not found")
+	ErrEmailTaken    = errors.New("email already in use")
+)