Add Java Display Animator plugin

[rieyi]

Plugin submission: Java Display Animator

Summary

Adds a complete Minecraft Java item-animation workflow with per-display-context preview controls, 20 FPS frame baking, resource-pack routing, and an animation-driving datapack.

Unlike a bare model-sequence exporter, this plugin generates the item definition, display-context routing, textures, frame models, datapack functions, validation report, and cleanup manifest needed for direct in-game testing. It registers its own independent model format and does not replace or modify formats registered by other plugins.

Source and reproducible build

Human-readable source and build instructions are available at:
https://github.com/rieyi/display-anim-preview

The official repository artifact can be reproduced with:

npm ci
npm test
npm run typecheck
npm run build:official

This produces dist/display_anim_preview.official.js, which is copied into this repository as plugins/display_anim_preview/display_anim_preview.js. The official build omits embedded About metadata because the current repository format supplies it through about.md.

Validation

• Tested in Blockbench Desktop 5.1.5 and 5.1.6
• Export tested in Minecraft Java 26.2
• English base interface with Simplified Chinese translations through Language.addTranslations
• npm test, npm run typecheck, npm run build:release, and npm run build:official pass
• npm run validate display_anim_preview passes against the current upstream validator
• Plugin bundle is approximately 121 KB; the 96×96 icon is approximately 1.1 KB