Add photo galleries API and frontend for public and admin viewing.

Introduces the Go photo-api service, nginx/systemd deploy wiring, and Next.js gallery/lightbox pages so event photos can be managed and browsed.

Co-authored-by: Cursor <cursoragent@cursor.com>

photo-api/internal/httpapi/respond.go

@@ -0,0 +1,39 @@
+package httpapi
+
+import (
+	"encoding/json"
+	"log"
+	"net/http"
+
+	"git.azzamo.net/Michilis/Spanglish/photo-api/internal/store"
+)
+
+func writeJSON(w http.ResponseWriter, status int, body any) {
+	w.Header().Set("Content-Type", "application/json")
+	w.WriteHeader(status)
+	if err := json.NewEncoder(w).Encode(body); err != nil {
+		log.Printf("write response: %v", err)
+	}
+}
+
+// writeError follows the backend's error shape: {"error": string}.
+func writeError(w http.ResponseWriter, status int, msg string) {
+	writeJSON(w, status, map[string]string{"error": msg})
+}
+
+// writeStoreError maps store errors: ErrNotFound -> 404, else 500 with the
+// backend's generic message (details go to the log, not the client).
+func writeStoreError(w http.ResponseWriter, err error, notFoundMsg string) {
+	if err == store.ErrNotFound {
+		writeError(w, http.StatusNotFound, notFoundMsg)
+		return
+	}
+	log.Printf("Error: %v", err)
+	writeError(w, http.StatusInternalServerError, "Internal Server Error")
+}
+
+func decodeJSON(r *http.Request, dst any) error {
+	dec := json.NewDecoder(http.MaxBytesReader(nil, r.Body, 1<<20))
+	dec.DisallowUnknownFields()
+	return dec.Decode(dst)
+}