Improve gallery video UX and add upload-to-publish media workflow.

Stage raw files in upload/, publish with make sync-media/publish, and polish the lightbox: autoplay, remembered volume, Escape to close, and image/video icons without poster or caption clutter.

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

docker-compose.yaml

@@ -9,6 +9,8 @@ services:
       - ./app/images:/app/images
     env_file:
       - .env
+    environment:
+      IMAGES_DIR: /app/images
     #networks:
     #  - caddy
     labels:
@@ -25,6 +27,7 @@ services:
       - "8080:8080"   # app direct (no auto-reload)
     volumes:
       - ./app:/app
+      - ./upload:/upload
       - ${GOMODCACHE}:/go/pkg/mod
       - ${GOCACHE}:/root/.cache/go-build
     env_file: