Add jukebox_maker web app v1.0

Go web application for filling USB drives with media files.
Runs in Docker on Unraid with /media, /mnt/usb, /config volumes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

ops/build-image.sh

@@ -0,0 +1,20 @@
+#!/bin/sh
+set -eu
+
+ROOT_DIR=$(CDPATH= cd -- "$(dirname "$0")/.." && pwd)
+
+if ! command -v docker >/dev/null 2>&1; then
+    echo "docker not found in PATH" >&2
+    exit 1
+fi
+
+IMAGE_NAME=${IMAGE_NAME:-jukebox-maker}
+DEFAULT_TAG=$(git -C "${ROOT_DIR}" rev-parse --short HEAD 2>/dev/null || echo dev)
+IMAGE_TAG=${1:-${IMAGE_TAG:-${DEFAULT_TAG}}}
+
+echo "building ${IMAGE_NAME}:${IMAGE_TAG}"
+docker build \
+    -f "${ROOT_DIR}/Dockerfile" \
+    -t "${IMAGE_NAME}:${IMAGE_TAG}" \
+    -t "${IMAGE_NAME}:latest" \
+    "${ROOT_DIR}"