diff --git a/docs/web-cad-implementation-plan.zh-CN.md b/docs/web-cad-implementation-plan.zh-CN.md
index 9002dab..0f5626f 100644
--- a/docs/web-cad-implementation-plan.zh-CN.md
+++ b/docs/web-cad-implementation-plan.zh-CN.md
@@ -1692,6 +1692,7 @@ DocumentSnapshot 现在区分模型树投影与 `DocumentObjectSnapshot` 真值
 | Data 编辑 | `PASS` | 浏览器将 Pad Length 从 42 改为 50，树版本 v18→v19、对象 Status→Touched、tree state→dirty |
 | View/Data 分离 | `PASS` | Visibility 等 View 属性提交文档事务但不把几何对象标记 Touched |
 | 类型控件 | `PASS` | View 标签由 metadata 生成 1 个 checkbox、2 个 enumeration、2 个 numeric、2 个 color 控件 |
+| Part primitive Task | `PASS` | Part 工作台任务可选择 Box/Cylinder/Sphere/Cone，尺寸和角度草稿写入 `Part::*` 对象属性并进入 OCCT 重算 |
 | 校验 | `PASS` | 负 Length、越界 Percent、未知 Enumeration、无效颜色、缺失 Link、只读 Property 在 Facade 拒绝 |
 | Undo/Redo | `PASS` | Length 42→50 可撤销回 42、重做至 50，Property 和树投影同步 |
 | SQLite/OPFS | `PASS` | Chrome `sqlite-opfs` 保存 v19 后重新加载 Length=61、Status=Touched、tree state=dirty |
diff --git a/src/App.tsx b/src/App.tsx
index d03602c..886038e 100644
--- a/src/App.tsx
+++ b/src/App.tsx
@@ -351,7 +351,7 @@ function TaskPanel({ workbench, facade, showNotice }: { workbench: Workbench; fa
   const primitiveUnits: Record<string, string> = { width: 'mm', length: 'mm', height: 'mm', radius: 'mm', radius1: 'mm', radius2: 'mm', angle: 'deg' }
   const primitiveFallbacks: Record<string, number> = { width: 10, length: 10, height: 10, radius: 5, radius1: 5, radius2: 0, angle: 360 }
   const primitiveLabel = (field: string) => field === 'radius1' ? 'Bottom radius' : field === 'radius2' ? 'Top radius' : field[0].toUpperCase() + field.slice(1)
-  return <div className="task-panel"><div className="task-actions-top"><button className="button button-primary" onClick={() => { facade.task.apply(); showNotice('Task accepted') }}>OK</button><button className="button button-outline" onClick={() => { facade.task.update({ preview: true }); showNotice('Preview applied') }}>Apply</button><button className="button button-quiet" onClick={() => { facade.task.cancel(); showNotice('Task cancelled') }}>Cancel</button></div><div className="task-header"><div className="task-icon"><Pencil size={16} /></div><div><span className="eyebrow">Active command</span><h2>{isSketch ? 'Edit Sketch' : definition.taskTitle}</h2></div><Badge tone="cyan">Preview</Badge></div><div className="task-body"><div className="task-step"><span className="step-index">1</span><div><strong>{isSketch ? 'Geometry and constraints' : definition.objectType}</strong><span>{definition.taskSummary}</span></div></div>{activeTask?.commandId === 'primitive' && <><label className="field-label">Primitive type<select className="field-input" value={primitiveType} onChange={(event) => facade.task.update({ primitiveType: event.target.value })}><option>Box</option><option>Cylinder</option><option>Sphere</option><option>Cone</option></select></label>{primitiveFields.map((field) => <label className="field-label" key={field}>{primitiveLabel(field)} <span className="field-unit">{primitiveUnits[field]}</span><input className="field-input" type="number" min={field === 'radius2' ? 0 : 0.001} step={primitiveUnits[field] === 'deg' ? 1 : 0.1} value={typeof activeTask.draft[field] === 'number' ? Number(activeTask.draft[field]) : primitiveFallbacks[field]} onChange={(event) => facade.task.update({ [field]: Number(event.target.value) })} /></label>)}</>}<label className="field-label">Primary value <span className="field-unit">mm</span><input className="field-input" value={isSketch ? 'Fully constrained' : '42.00'} readOnly /></label><label className="field-label">Operation<select className="field-input"><option>{workbench === 'Part Design' ? 'Dimension' : 'Contextual preview'}</option><option>Through all</option><option>Up to face</option></select></label><label className="check-row"><input type="checkbox" defaultChecked /><span>Preview result in viewport</span></label><div className="task-note"><AlertTriangle size={14} /><span>Changes remain local until the document is recomputed.</span></div></div></div>
+  return <div className="task-panel"><div className="task-actions-top"><button className="button button-primary" onClick={() => { facade.task.apply(); showNotice('Task accepted') }}>OK</button><button className="button button-outline" onClick={() => { facade.task.update({ preview: true }); showNotice('Preview applied') }}>Apply</button><button className="button button-quiet" onClick={() => { facade.task.cancel(); showNotice('Task cancelled') }}>Cancel</button></div><div className="task-header"><div className="task-icon"><Pencil size={16} /></div><div><span className="eyebrow">Active command</span><h2>{isSketch ? 'Edit Sketch' : definition.taskTitle}</h2></div><Badge tone="cyan">Preview</Badge></div><div className="task-body"><div className="task-step"><span className="step-index">1</span><div><strong>{isSketch ? 'Geometry and constraints' : definition.objectType}</strong><span>{definition.taskSummary}</span></div></div>{activeTask?.commandId === 'primitive' && <><label className="field-label">Primitive type<select className="field-input" value={primitiveType} onChange={(event) => facade.task.update({ primitiveType: event.target.value })}><option>Box</option><option>Cylinder</option><option>Sphere</option><option>Cone</option></select></label>{primitiveFields.map((field) => <label className="field-label" key={field}>{primitiveLabel(field)} <span className="field-unit">{primitiveUnits[field]}</span><input className="field-input" type="number" min={field === 'radius2' ? 0 : 0.001} step={primitiveUnits[field] === 'deg' ? 1 : 0.1} value={typeof activeTask.draft[field] === 'number' ? Number(activeTask.draft[field]) : primitiveFallbacks[field]} onChange={(event) => facade.task.update({ [field]: Number(event.target.value) })} /></label>)}</>}{activeTask?.commandId !== 'primitive' && <><label className="field-label">Primary value <span className="field-unit">mm</span><input className="field-input" value={isSketch ? 'Fully constrained' : '42.00'} readOnly /></label><label className="field-label">Operation<select className="field-input"><option>{workbench === 'Part Design' ? 'Dimension' : 'Contextual preview'}</option><option>Through all</option><option>Up to face</option></select></label></>}<label className="check-row"><input type="checkbox" defaultChecked /><span>Preview result in viewport</span></label><div className="task-note"><AlertTriangle size={14} /><span>Changes remain local until the document is recomputed.</span></div></div></div>
 }
 
 function PropertyPanel({ facade, objectId, scope, showNotice }: { facade: BitBybitWebCadFacade; objectId: string; scope: 'data' | 'view'; showNotice: (message: string) => void }) {