1.21.1 - 1.1.0

New Utilities

• Added util.ModCompat.isLoaded(String modId) — a one-line check for whether another mod is loaded, replacing hand-rolled per-mod loader enums.
• Added util.RomanNumeralUtil.generate(int) — converts an int to a Roman numeral string.

New Client Rendering Helpers

• Added client.util.PoseStackHelper.translateAndScale/rotateItem — common PoseStack transforms for drawing an ItemStack at an offset inside a block entity renderer.
• Added client.util.RenderingUtils.swing/flap/bob/walk — limb-animation math for ModelParts.

New Config/GUI Helpers

• Added client.config.RegistryCandidates — turns a built-in or datapack registry (entities, items, blocks, attributes, enchantments, biomes) into a searchable candidate list for EntryPickerScreen, including a fallback for datapack-driven registries (biomes, enchantments) when no world is loaded, e.g. editing config from the title screen.
• Added a second, heavier config-list editor for pipe-delimited, multi-field config rows: client.config.RuleType (field schema with per-field validation), RuleSuggestionSource (caller-supplied id lookups), RuleListContext (translation key prefixes), RuleListScreen and RuleEditScreen. This complements the existing append-only PickerListScreen for config lists that need several validated fields per row, edited in place.
• Added ConfigHelper.getOrDefault/ConfigHolder.getOrDefault — a guard that returns a fallback instead of throwing IllegalStateException when a config value is read before its spec is loaded (e.g. datagen or other contexts where no config file is ever loaded, such as a block's isEnabled(FeatureFlagSet) check running under the loot table provider).

Internal Cleanup

• No breaking changes to existing public APIs.