Refactor loadDictionary to accept a file path and support both legacy
bare-array (version 0) and versioned object formats. Add background
sync that fetches the latest games.json from GitHub, uses ETag-based
conditional requests (304 support), atomic cache writes, and hot-swaps
processMap/gameEntries without resetting current detection state.
On startup, the best local source (cache vs bundled seed) is loaded
immediately for instant detection, then sync runs fire-and-forget.
Jannis Braun
948fa6de5c