修正 model3d 绑定生成的 editor_canvas 测试过滤词

- package.json：contracts:model3d:generate 的测试过滤词由 editorcanvas 改为 editor_canvas；libtest 过滤词按子串区分大小写，而模块名是 editor_canvas::export_bindings_*，原写法命中 0 个用例，packages/shared/src/contracts/editor-canvas 实际只被 prettier 重排、从未重新生成

验证：cargo test --locked -p shared-contracts -- model3d editor_canvas（25 个导出用例命中，含 editor_canvas 的 2 个；修复前该过滤词命中 0 个）、npm run contracts:model3d:generate 后 packages/shared 零 diff

package.json

@@ -44,7 +44,7 @@
     "admin-web:typecheck": "node scripts/admin-web-build.mjs typecheck",
     "admin-web:preview": "npm --prefix apps/admin-web run preview --",
     "spacetime:generate": "node scripts/generate-spacetime-bindings.mjs",
-    "contracts:model3d:generate": "cargo test --locked -p shared-contracts --manifest-path server-rs/Cargo.toml -- model3d editorcanvas && prettier --write packages/shared/src/contracts/model3d packages/shared/src/contracts/editor-canvas",
+    "contracts:model3d:generate": "cargo test --locked -p shared-contracts --manifest-path server-rs/Cargo.toml -- model3d editor_canvas && prettier --write packages/shared/src/contracts/model3d packages/shared/src/contracts/editor-canvas",
     "spacetime:external-generation:maintain": "node scripts/spacetime-maintain-external-generation-jobs.mjs",
     "spacetime:editor-image-asset-kind:clean": "node scripts/spacetime-clean-editor-image-asset-kind.mjs",
     "spacetime:editor-canvas-layout:migrate": "node scripts/spacetime-migrate-editor-canvas-layout.mjs",