Mods are folders with About/About.json metadata; ModLoader resolves a
deterministic load order (dependencies first, ties alphabetical) and
later mods override earlier ones everywhere.
DefDatabase loads JSON def files ({ "type", "defs": [...] }) into
game-registered Def subclasses, with parent inheritance (own fields on
top of the parent's, nested values replaced whole), abstract parents
and full replacement of same-named defs by later mods.
LanguageManager loads Languages/<code>/*.json flat key-string maps,
switches language at runtime and falls back current -> default -> key.
ModContentTree merges one content folder across mods by relative path;
AtlasBuilder gains an explicit-sources Build overload so a merged
texture tree can be packed incrementally at game start.
The LittleSim game now ships its entire content as the Core mod,
demonstrating the module end to end.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
