Add albums support, API layer, and Docker improvements

- Add albums browsing and navigation (src/albums.c, src/app.c)
- Extract API calls into dedicated src/api.c module
- Improve display and UI components
- Update CMakeLists.txt to include new source files
- Refactor Dockerfile for better build process

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

src/main.c

@@ -158,6 +158,7 @@ static char (*g_tex_err)[160];
 #include "display.c"   /* merged server+local timeline + grid layout     */
 #include "ui.c"        /* grid/detail/search/login/cloud screens         */
 #include "map.c"       /* geotag map: markers, clustering, projection    */
+#include "albums.c"    /* album list page + album open/fetch threads     */
 #include "video.c"     /* video download + SceAvPlayer playback          */
 #include "sync.c"      /* local scan/hash/check/upload + sync overview   */
 #include "app.c"       /* main(): init, event loop, threads             */