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/api/guests.go

@@ -0,0 +1,114 @@
+package api
+
+import (
+	"encoding/json"
+	"errors"
+	"net/http"
+
+	"github.com/alchemistkay/guestguard/internal/domain"
+	"github.com/alchemistkay/guestguard/internal/storage"
+)
+
+type guestHandler struct {
+	guests *storage.GuestRepo
+	events *storage.EventRepo
+}
+
+type createGuestRequest struct {
+	Name         string  `json:"name"`
+	Email        *string `json:"email"`
+	Phone        *string `json:"phone"`
+	PlusOnes     int     `json:"plus_ones"`
+	DietaryNotes *string `json:"dietary_notes"`
+	TableNumber  *int    `json:"table_number"`
+}
+
+func (h *guestHandler) create(w http.ResponseWriter, r *http.Request) {
+	eventID, ok := parseIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	if _, err := h.events.Get(r.Context(), eventID); err != nil {
+		if errors.Is(err, domain.ErrEventNotFound) {
+			writeError(w, http.StatusNotFound, "event not found")
+			return
+		}
+		writeError(w, http.StatusInternalServerError, "failed to load event")
+		return
+	}
+
+	var req createGuestRequest
+	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
+		writeError(w, http.StatusBadRequest, "invalid json")
+		return
+	}
+	if req.Name == "" {
+		writeError(w, http.StatusBadRequest, "name is required")
+		return
+	}
+	if req.PlusOnes < 0 {
+		writeError(w, http.StatusBadRequest, "plus_ones must be >= 0")
+		return
+	}
+
+	g, err := h.guests.Create(r.Context(), storage.CreateGuestParams{
+		EventID:      eventID,
+		Name:         req.Name,
+		Email:        req.Email,
+		Phone:        req.Phone,
+		PlusOnes:     req.PlusOnes,
+		DietaryNotes: req.DietaryNotes,
+		TableNumber:  req.TableNumber,
+	})
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to create guest")
+		return
+	}
+	writeJSON(w, http.StatusCreated, g)
+}
+
+func (h *guestHandler) list(w http.ResponseWriter, r *http.Request) {
+	eventID, ok := parseIDParam(w, r, "id")
+	if !ok {
+		return
+	}
+	q := r.URL.Query()
+	limit := atoiOr(q.Get("limit"), 100)
+	offset := atoiOr(q.Get("offset"), 0)
+
+	guests, err := h.guests.ListByEventWithRSVP(r.Context(), eventID, limit, offset)
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, "failed to list guests")
+		return
+	}
+	if guests == nil {
+		guests = []*storage.GuestWithRSVP{}
+	}
+
+	stats := struct {
+		Total     int `json:"total"`
+		Attending int `json:"attending"`
+		Declined  int `json:"declined"`
+		Maybe     int `json:"maybe"`
+		Pending   int `json:"pending"`
+	}{Total: len(guests)}
+	for _, g := range guests {
+		switch {
+		case g.RSVPResponse == nil:
+			stats.Pending++
+		case *g.RSVPResponse == string(domain.RSVPAttending):
+			stats.Attending++
+		case *g.RSVPResponse == string(domain.RSVPDeclined):
+			stats.Declined++
+		case *g.RSVPResponse == string(domain.RSVPMaybe):
+			stats.Maybe++
+		}
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{
+		"guests": guests,
+		"stats":  stats,
+		"limit":  limit,
+		"offset": offset,
+	})
+}