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/storage/local.go

@@ -0,0 +1,91 @@
+package storage
+
+import (
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+	"time"
+)
+
+// local stores objects under root (STORAGE_PATH, default ./data/photos).
+// Deliberately disjoint from backend/uploads; nothing here is ever served
+// statically — all reads go through the access-checked files handler.
+type local struct {
+	root string
+}
+
+func newLocal(root string) (*local, error) {
+	if err := os.MkdirAll(root, 0o755); err != nil {
+		return nil, fmt.Errorf("create storage dir %s: %w", root, err)
+	}
+	return &local{root: root}, nil
+}
+
+// path validates the key stays inside root (keys are generated internally,
+// but defense-in-depth costs one Clean call).
+func (l *local) path(key string) (string, error) {
+	clean := filepath.Clean("/" + key)
+	if strings.Contains(clean, "..") {
+		return "", fmt.Errorf("invalid key %q", key)
+	}
+	return filepath.Join(l.root, clean), nil
+}
+
+func (l *local) Put(_ context.Context, key string, r io.Reader, _ int64, _ string) error {
+	dst, err := l.path(key)
+	if err != nil {
+		return err
+	}
+	if err := os.MkdirAll(filepath.Dir(dst), 0o755); err != nil {
+		return err
+	}
+	tmp, err := os.CreateTemp(filepath.Dir(dst), ".upload-*")
+	if err != nil {
+		return err
+	}
+	defer os.Remove(tmp.Name())
+	if _, err := io.Copy(tmp, r); err != nil {
+		tmp.Close()
+		return err
+	}
+	if err := tmp.Close(); err != nil {
+		return err
+	}
+	return os.Rename(tmp.Name(), dst)
+}
+
+func (l *local) Open(_ context.Context, key string) (io.ReadCloser, int64, error) {
+	p, err := l.path(key)
+	if err != nil {
+		return nil, 0, err
+	}
+	f, err := os.Open(p)
+	if err != nil {
+		return nil, 0, err
+	}
+	info, err := f.Stat()
+	if err != nil {
+		f.Close()
+		return nil, 0, err
+	}
+	return f, info.Size(), nil
+}
+
+func (l *local) Delete(_ context.Context, key string) error {
+	p, err := l.path(key)
+	if err != nil {
+		return err
+	}
+	err = os.Remove(p)
+	if os.IsNotExist(err) {
+		return nil
+	}
+	return err
+}
+
+func (l *local) PresignGet(context.Context, string, string, string, time.Duration) (string, error) {
+	return "", ErrNoPresign
+}