minecraft-mod-architecturelisted

# Minecraft Mod Architecture ## Purpose Everything a mod adds must be *registered*, at the right time, on the right side, through the loader's own mechanism. Get the timing wrong and the registry is frozen and throws; get the side wrong and the dedicated server dies with `NoClassDefFoundError` on a class that only exists on the client. This skill gives the structural rules that make both classes of failure impossible by construction, on each loader separately. ## When to use - Setting up a new mod, or adding the first block, item, entity or block entity and needing somewhere for it to live. - A crash occurs during mod loading, or the game logs "registry is frozen", "Registry object not present", or a null static field at startup. - The dev client runs but `runServer` crashes, or players report the server crashing while the single-player world is fine. - Deciding where a class belongs when it touches both game logic and rendering. ## When NOT to use - The loader, version and mappings are not yet resolved. Run `minecraft-project-conventions` first; this skill assumes the triple is known. - The question is about a specific content type's own API surface. Use `minecraft-blocks-items`, `minecraft-entities-mobs` or `minecraft-gui-screens` for those; this skill covers only where they plug in and when. - Cross-loader abstraction of a mod that must ship on both. That is `minecraft-loader-portability`. ## Required context - **Loader** (Fabric or NeoForge), **Minec