feat: CEO plan preview & confirm before company execution

- Add POST /companies/{id}/plan endpoint for stateless CEO plan preview (no DB write)
- execute()/execute_stream() accept optional confirmed ceo_plan to skip re-planning
- Frontend: plan preview dialog in CompanyBuilder to review/tweak analysis, dept goals & deliverables before running; previewCompanyPlan API with extended timeout
- Grant file_write tool to CEO/CTO presets; add echarts dependency

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/app/api/companies.py

@@ -60,6 +60,9 @@ class DepartmentAdd(BaseModel):
 
 class ExecuteRequest(BaseModel):
     project_description: str = Field(..., min_length=1, description="公司级项目目标")
+    ceo_plan: Optional[Dict[str, Any]] = Field(
+        None, description="已确认的 CEO 计划；提供时跳过二次规划，直接据此执行"
+    )
 
 
 # ─── Endpoints ───
@@ -365,6 +368,24 @@ def remove_department(
 # ─── 项目执行 ───
 
 
+@router.post("/{company_id}/plan")
+async def plan_company(
+    company_id: str,
+    body: ExecuteRequest,
+    db: Session = Depends(get_db),
+    current_user: User = Depends(get_current_user),
+):
+    """仅生成 CEO 计划供预览/确认，不派发部门、不落库。"""
+    company = db.query(Company).filter(Company.id == company_id).first()
+    if not company:
+        raise HTTPException(status_code=404, detail="公司不存在")
+    orchestrator = CompanyOrchestrator(db, company_id, current_user.id)
+    try:
+        return await orchestrator.preview_plan(body.project_description)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+
+
 @router.post("/{company_id}/execute")
 async def execute_company(
     company_id: str,
@@ -378,7 +399,7 @@ async def execute_company(
         raise HTTPException(status_code=404, detail="公司不存在")
     orchestrator = CompanyOrchestrator(db, company_id, current_user.id)
     try:
-        result = await orchestrator.execute(body.project_description)
+        result = await orchestrator.execute(body.project_description, ceo_plan=body.ceo_plan)
         return result
     except ValueError as e:
         raise HTTPException(status_code=400, detail=str(e))
@@ -400,7 +421,7 @@ async def execute_company_stream(
 
     async def event_stream():
         try:
-            async for event in orchestrator.execute_stream(body.project_description):
+            async for event in orchestrator.execute_stream(body.project_description, ceo_plan=body.ceo_plan):
                 yield f"data: {json.dumps(event, ensure_ascii=False)}\n\n"
         except Exception as e:
             yield f"data: {json.dumps({'type': 'error', 'message': str(e)}, ensure_ascii=False)}\n\n"