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/imaging/heic.go

@@ -0,0 +1,60 @@
+package imaging
+
+import (
+	"fmt"
+	"os/exec"
+)
+
+// HEIC cannot be decoded in pure Go (HEVC), so conversion shells out to a
+// host-installed CLI. The Go binary itself stays cgo-free; the converter is
+// a runtime dependency (Debian: libvips-tools or libheif-examples).
+type HeicConverter struct {
+	kind string // "vips" | "heif-convert" | "custom"
+	path string
+}
+
+// DetectHeicConverter honors an explicit HEIC_CONVERTER command, else
+// autodetects vips then heif-convert. Returns nil when none is available;
+// uploads of HEIC are then rejected with a clear message.
+func DetectHeicConverter(explicit string) *HeicConverter {
+	if explicit != "" {
+		if p, err := exec.LookPath(explicit); err == nil {
+			return &HeicConverter{kind: "custom", path: p}
+		}
+		return nil
+	}
+	if p, err := exec.LookPath("vips"); err == nil {
+		return &HeicConverter{kind: "vips", path: p}
+	}
+	if p, err := exec.LookPath("heif-convert"); err == nil {
+		return &HeicConverter{kind: "heif-convert", path: p}
+	}
+	return nil
+}
+
+func (h *HeicConverter) Name() string { return h.path }
+
+// ToJPEG converts src (a .heic file) to a JPEG at dst.
+func (h *HeicConverter) ToJPEG(src, dst string) error {
+	var cmd *exec.Cmd
+	switch h.kind {
+	case "vips":
+		cmd = exec.Command(h.path, "copy", src, dst+"[Q=95]")
+	case "heif-convert":
+		cmd = exec.Command(h.path, "-q", "95", src, dst)
+	default:
+		// custom converter contract: <cmd> <src> <dst>
+		cmd = exec.Command(h.path, src, dst)
+	}
+	if out, err := cmd.CombinedOutput(); err != nil {
+		return fmt.Errorf("heic conversion failed: %v: %s", err, truncate(string(out), 300))
+	}
+	return nil
+}
+
+func truncate(s string, n int) string {
+	if len(s) > n {
+		return s[:n]
+	}
+	return s
+}