feat: Excel导入支持自定义列映射+智能列名检测

- 上传后自动读取Excel列名，下拉框选择映射
- 智能匹配: 科目/编码→kpi_code, 期间→period, 金额→actual_value
- 支持统一期间(文件无期间列时)
- 后端接受 kpi_col/period_col/value_col/default_period 参数

backend/app/api/data.py

@@ -15,14 +15,24 @@ router = APIRouter(prefix="/api/cma/data", tags=["数据对接"],
 )
 
 @router.post("/import-excel")
-async def import_excel(file: UploadFile = File(...), db: Session = Depends(get_db)):
+async def import_excel(file: UploadFile = File(...),
+                       kpi_col: str = Query("kpi_code", description="Excel中KPI编码列名"),
+                       period_col: str = Query("period", description="Excel中期间列名"),
+                       value_col: str = Query("actual_value", description="Excel中实际值列名"),
+                       default_period: str = Query(None, description="如文件无期间列，统一使用此值"),
+                       db: Session = Depends(get_db)):
     content = await file.read()
     df = pd.read_excel(io.BytesIO(content))
 
-    required = ["kpi_code", "period", "actual_value"]
-    if not all(c in df.columns for c in required):
-        raise HTTPException(400, f"Excel必须包含列: {required}")
-    
+    required = [kpi_col, value_col]
+    if not default_period:
+        required.append(period_col)
+
+    missing = [c for c in required if c not in df.columns]
+    if missing:
+        raise HTTPException(400,
+            f"Excel缺少列: {missing}。当前文件列: {list(df.columns)}")
+
     if len(df) == 0:
         raise HTTPException(400, "Excel文件为空，没有数据行")
     
@@ -33,9 +43,9 @@ async def import_excel(file: UploadFile = File(...), db: Session = Depends(get_d
     count = 0
     skipped = []
     for idx, row in df.iterrows():
-        kpi_code = str(row.get("kpi_code", "")).strip()
-        period = str(row.get("period", "")).strip()
-        value = row.get("actual_value")
+        kpi_code = str(row.get(kpi_col, "")).strip()
+        period = str(row.get(period_col, default_period or "")).strip() if period_col in df.columns else (default_period or "").strip()
+        value = row.get(value_col)
         
         if not kpi_code or not period or pd.isna(value):
             skipped.append(f"第{idx+2}行: 缺少必填字段")