feat: 多工厂/厂间调拨/替代料/流水台账折叠 + 重写 README

- 多工厂(factory 表) + 顶栏工厂下拉过滤, 库存按厂聚合
- 厂间调拨(transfer): 源厂减+目标厂加, 总库存不变, 双向流水对账
- 替代料关系(substitute): 出库/BOM领料/生产领料缺料时提示可替代料
- 流水台账(ledger): 入出按日期合并折叠, 按日期导出同一 Excel
- 生产订单增强: 编辑/删除(级联清关联流水)/调入数量/确认调入=厂间调拨
- 入库新增送货日期字段; 出库物料编码扫码定位
- 重写 README 补全全部模块; .gitignore 排除 dist_pkg/build_pkg/*.db
- 停止跟踪 instance/app.db(运行时自动生成)

excel_io.py

@@ -118,7 +118,7 @@ def read_materials(path):
     return out
 
 
-def import_materials(rows, operator="导入"):
+def import_materials(rows, operator="导入", factory_id=None):
     """upsert 物料; opening_stock>0 写入一条"期初"入库流水。返回 (新增, 更新)"""
     added = 0
     updated = 0
@@ -138,11 +138,12 @@ def import_materials(rows, operator="导入"):
         op = d.get("opening_stock", 0) or 0
         if op > 0:
             exists = db.session.scalar(
-                db.select(Inbound).where(Inbound.material_id == m.id, Inbound.source == "期初"))
+                db.select(Inbound).where(Inbound.material_id == m.id, Inbound.source == "期初",
+                                         Inbound.factory_id == factory_id))
             if exists:
                 exists.qty = op
             else:
-                db.session.add(Inbound(material_id=m.id, qty=op, source="期初",
+                db.session.add(Inbound(material_id=m.id, factory_id=factory_id, qty=op, source="期初",
                                        occur_date=date.today(), operator=operator))
     db.session.commit()
     return added, updated
@@ -256,6 +257,47 @@ def build_material_template(path):
     return path
 
 
+def export_ledger(target, rows):
+    """导出流水台账。target 可为路径或文件对象(如 BytesIO)。
+
+    rows: _build_ledger_rows() 返回的流水行列表, 每项含
+    date/type/cat/m/qty/fac/who/ref/op 字段。
+    """
+    wb = Workbook()
+    ws = wb.active
+    ws.title = "流水台账"
+    head = ["日期", "类型", "业务类型", "物料编号", "型号/规格", "单位",
+            "数量", "工厂", "来源/用途", "调拨/关联单号", "经手人"]
+    ws.append(head)
+    for c in ws[1]:
+        c.font = Font(bold=True)
+        c.fill = PatternFill("solid", fgColor="DDEBF7")
+    for r in rows:
+        m = r["m"]
+        ws.append([
+            r["date"].isoformat() if r["date"] else "",
+            r["type"],
+            r["cat"],
+            m.part_number if m else "",
+            m.manufacturer if m else "",
+            m.unit if m else "",
+            r["qty"],
+            r["fac"].code if r["fac"] else "",
+            r["who"] or "",
+            r["ref"] or "",
+            r["op"] or "",
+        ])
+    # 出入着色: 入(绿) / 出(红)
+    for i in range(2, ws.max_row + 1):
+        tval = ws.cell(row=i, column=2).value
+        if tval == "入":
+            ws.cell(row=i, column=2).fill = PatternFill("solid", fgColor="C6EFCE")
+        elif tval == "出":
+            ws.cell(row=i, column=2).fill = PatternFill("solid", fgColor="FFC7CE")
+    ws.freeze_panes = "A2"
+    wb.save(target)
+
+
 def build_bom_template(path):
     """生成与真实 BOM 模板一致的格式(Altium/嘉立创导出):
     每个 worksheet 一个 BOM, sheet 名即 BOM 型号; 列头 Item/Part Number/