Update Java Display Animator to 1.1.2

[rieyi]

Update Java Display Animator to 1.1.2

Update the existing plugin added in #968 with a project settings panel, first-person animation authoring preview, and optional player-skin arms.

Improvements and new features

• Group plugin commands under Tools > Java Display Animator. A six-page settings window manages General, Player Arms, Animations, Pack Files, Datapack, and Developer API settings. Changes update the current project; users save the .bbmodel to retain them on disk.
• Provide a first-person preview panel in the Animate sidebar to preview the first-person result while editing animations.
• Add player-arm support.
• Support multiple animation tracks, 1–20 FPS sampling, isolated baking, model-frame deduplication, bounds checks, and transactional insertion into existing packs.

Fixes

• Hide internal animation and export object properties from the native project form with exposed: false, preserving their serialization.
• Add pack export to File > Export and inherit Blockbench text sizing for small labels, hints, and bounds results.
• Register the Tools submenu once and keep one first-person timeline button after hot reloads.
• Open the display-animation controls automatically for new Java Display Animation projects, expanding a folded panel and preserving existing display switches.
• Correct native dialog cancellation indices so closing or pressing Escape cancels bounds selection, export confirmation, and hand deletion.

Validation

• Automated source tests, type checking, and universal/Chinese/official builds pass for 1.1.2.
• The upstream plugin validator passes for display_anim_preview.
• Blockbench Desktop 5.2.1: project settings, automatic preview opening, folded-panel reopening, cancellation, player-arm version notices, and hot reloads were checked on authorized test copies. The source model retains four keyframes and its model, texture, display, and export settings after verification and restoration.

The declared minimum is Blockbench Desktop 5.1.5; live checks used 5.2.1.