ChessBoard

New Features
1. Board Material Variant System (a6a4466 + ea8dbcf)

New ChessWood/ChessMaterial enum: 12 materials (7 stripped logs + 5 polished stones), with Chinese display names
Boards gained wood and frameless block-state properties: 4 board types × 12 materials × framed/frameless = 96 variants
Each variant is a distinct item (block_state + custom_model_data + custom_name components), shown in the creative tab and craftable via stonecutting per material
Variant is preserved when the board drops; can be changed anytime via /chessboard wood or the GUI
2. Custom Piece Materials (ea8dbcf)

New MaterialData with 6 material slots: Chinese Chess / Chess White / Chess Black / Gomoku Black / White / Gray
New ChessPieceBlock (material property) — pieces render with configurable materials, all piece blockstates support switching
New SetMaterialPayload network packet: client changes material → server writes block entity → auto-synced (multiplayer-ready)
All 12 Chess piece models (king/queen/bishop/knight/rook/pawn × white/black) integrated into the renderer
3. Reworked Management Screen (ea8dbcf)

New UI background (configui.png); left column: Import / Copy / Undo / Right-click toggle
Right column dropdowns: Opening mode (default/dark/full-dark/random), Board material, Piece materials (per-slot, scrollable)
New commands like /chessboard wood, /chessboard import; GUI actions take effect server-side via commands/network
Fixes
Crash opening the screen on 26.2 (62e5ada): reflection fallback between setScreen (26.1) and setScreenAndShow (26.2)
Missing particle textures on piece models (0f0c493): added particle references to piece_flat/tictactoe_pieces, clearing warnings for 71 models
Crafted boards showing raw translation keys (0f0c493): 92 recipes' custom_name reverted from string form to object form — 26.1 removed the CustomName wrapper, so the string form was treated as literal text
Polished stone variant recipes failing to load (0f0c493): removed the nonexistent stripped_polished_*_log ingredients from 40 recipes (previously those recipes failed to parse entirely)
Improvements
Rendering performance (0f0c493): piece model render states cached per (board, piece, material) — no more per-frame re-resolution (Gomoku at 225 stones/frame → near-zero resolution); allocation-free gridPos; off-screen boards no longer render (shouldRenderOffScreen back to false)
Code refactoring (0f0c493): new PlaceGameLogic interface (shared placement logic for Gomoku/TicTacToe); onClickMove/onUndo promoted to interface defaults; templated block/command registration; unified variantStack() for variant items; material serialization merged from 6 duplicated sites into helpers