RDL v0.1.2 Preview — remembered addons

Fixed Optional Addons disappearing after closing the launcher.

• The current addon list and load order now save automatically when adding, removing or moving addons, and on exit.
• RDL restores these addons at startup without requiring a named saved setup. The restored list also survives a collection refresh.
• Removing every addon preserves an empty list. Older settings files open safely. Existing named setups and artwork remain intact.

Validation: all 98 regression checks pass. Seven focused checks exercised the actual launcher add/reorder/remove controls, close-and-reopen restoration, restored list display, refresh, an intentionally empty list and older settings.

If your earlier addon list was already lost, re-add it once after updating or load an existing named setup; RDL will remember it from then on.

This remains a preview build. No games, engines, maps, mods, source code or developer tools are included.