Intern wurde ein größeres Refactoring durchgeführt. Für Endnutzer ist lediglich relevant, dass der Key "upload_movies" in der Config durch "upload_videos" ersetzt wurde.

Breaking Changes
* upload_movies renamed to upload_videos — The INI config key upload_movies has been renamed to upload_videos across all channels (Telegram, Discord, ntfy, Immich). Update your config.ini accordingly.

New Features & Architecture
* Modular channel architecture — Upload channels (Telegram, Discord, ntfy, Immich) are now fully self-contained modules under src/channels/. Each channel has its own .hpp + .cpp pair encapsulating:
** Config struct with defaults, load(), and validate()
** send(path) upload function
** Enabled state (no more separate flags in Config)
* X-macro channel registry (channels/channels.inc) — All channels are registered via X-macro, enabling automatic expansion in config.hpp/cpp and main.cpp. Adding a new channel now only requires: registering in channels.inc + creating channels/xxx.hpp + channels/xxx.cpp.

Bug Fixes
* Fixed a dangling pointer issue in the main loop.
* Fixed Immich config comment typo in config.ini.template.