feat(api): add endpoint to fetch guest list

* implement ListGuests method in store
* create handleGuestList function in API
* add GuestListEntry and GuestList interfaces in UI
* create guest list page to display RSVPs

server/internal/api/handlers.go

@@ -33,6 +33,7 @@ func (s *Server) Routes(mux *http.ServeMux) {
 	mux.HandleFunc("GET /healthz", s.handleHealthz)
 	mux.HandleFunc("GET /api/config", s.handleConfig)
 	mux.HandleFunc("POST /api/rsvp", s.handleRSVP)
+	mux.HandleFunc("GET /api/guests", s.handleGuestList)
 	mux.HandleFunc("POST /api/photos/upload", s.handlePhotoUpload)
 }
 
@@ -108,6 +109,38 @@ func (s *Server) handleRSVP(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusCreated, map[string]bool{"ok": true})
 }
 
+type guestResponse struct {
+	Name    string `json:"name"`
+	IsChild bool   `json:"isChild"`
+}
+
+func (s *Server) handleGuestList(w http.ResponseWriter, r *http.Request) {
+	guests, err := s.store.ListGuests()
+	if err != nil {
+		log.Printf("guests: list failed: %v", err)
+		writeError(w, http.StatusInternalServerError, "could not load guests")
+		return
+	}
+
+	out := make([]guestResponse, 0, len(guests))
+	adults, children := 0, 0
+	for _, g := range guests {
+		out = append(out, guestResponse{Name: g.Name, IsChild: g.IsChild})
+		if g.IsChild {
+			children++
+		} else {
+			adults++
+		}
+	}
+
+	writeJSON(w, http.StatusOK, map[string]any{
+		"guests":   out,
+		"total":    len(out),
+		"adults":   adults,
+		"children": children,
+	})
+}
+
 var allowedImageTypes = map[string]bool{
 	"image/jpeg": true,
 	"image/png":  true,