feat: 前后端全量开发 v0.2

后端:
- 客户模块 CRUD+搜索 (api/services/repositories 分层)
- 合同模块: FG单号规则/意向单转正式单/订单创建自动快照客户信息
- 优化下料: FFD首递减装箱算法(利用率统计/余料/未排入清单)
前端 (Vue3+TS+Element Plus):
- 7页面: 登录/工作台/订单中心/合同/客户/样板库/优化下料
- 自研二维窗型画布渲染器: 解析drawing_data渲染玻璃区域/外框/
  扇开向标记/尺寸标注, 支持缩放平移复位
- 样板库与订单联动(用此样板下单自动带图纸)
- axios统一envelope拦截/登录守卫/付费墙提示
工程:
- SPA history 回退路由, 构建产物挂载后端
- 全接口回归 6/6 通过

src/huamenchuang/repositories/contract_repo.py

@@ -0,0 +1,55 @@
+"""合同数据访问层。"""
+import datetime
+
+from sqlalchemy import func, or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from huamenchuang.models.contract import Contract
+
+STATUS_LABELS = {0: "意向单", 1: "正式单", 2: "已完成", 3: "已作废"}
+
+
+class ContractRepository:
+    def __init__(self, db: AsyncSession) -> None:
+        self.db = db
+
+    async def next_contract_no(self, company_id: int) -> str:
+        """合同号：FG+YYYYMMDD+3位流水（对齐目标站 FG20260818009 风格）。"""
+        today = datetime.date.today().strftime("%Y%m%d")
+        prefix = f"FG{today}"
+        stmt = select(Contract.contract_no).where(
+            Contract.company_id == company_id, Contract.contract_no.like(f"{prefix}%")
+        ).order_by(Contract.contract_no.desc()).limit(1)
+        last = (await self.db.execute(stmt)).scalar_one_or_none()
+        seq = int(last[-3:]) + 1 if last else 1
+        return f"{prefix}{seq:03d}"
+
+    async def get(self, contract_id: int, company_id: int) -> Contract | None:
+        stmt = select(Contract).where(Contract.id == contract_id, Contract.company_id == company_id)
+        return (await self.db.execute(stmt)).scalar_one_or_none()
+
+    async def search(self, company_id: int, page: int, page_size: int, keyword: str = "",
+                     status: int | None = None) -> tuple[list[Contract], int]:
+        conds = [Contract.company_id == company_id]
+        if status is not None:
+            conds.append(Contract.status == status)
+        if kw := keyword.strip():
+            like = f"%{kw}%"
+            conds.append(or_(Contract.contract_no.like(like), Contract.customer_name.like(like), Contract.phone.like(like)))
+        where = *conds,
+        total = (await self.db.execute(select(func.count()).select_from(Contract).where(*where))).scalar_one()
+        stmt = (select(Contract).where(*where).order_by(Contract.id.desc())
+                .offset((page - 1) * page_size).limit(page_size))
+        return list((await self.db.execute(stmt)).scalars()), total
+
+    async def create(self, contract: Contract) -> Contract:
+        self.db.add(contract)
+        await self.db.flush()
+        return contract
+
+    async def delete(self, contract: Contract) -> None:
+        await self.db.delete(contract)
+
+
+def status_label(status: int) -> str:
+    return STATUS_LABELS.get(status, "未知")

src/huamenchuang/repositories/customer_repo.py

@@ -0,0 +1,33 @@
+"""客户数据访问层。"""
+from sqlalchemy import func, or_, select
+from sqlalchemy.ext.asyncio import AsyncSession
+
+from huamenchuang.models.contract import Customer
+
+
+class CustomerRepository:
+    def __init__(self, db: AsyncSession) -> None:
+        self.db = db
+
+    async def get(self, customer_id: int, company_id: int) -> Customer | None:
+        stmt = select(Customer).where(Customer.id == customer_id, Customer.company_id == company_id)
+        return (await self.db.execute(stmt)).scalar_one_or_none()
+
+    async def search(self, company_id: int, page: int, page_size: int, keyword: str = "") -> tuple[list[Customer], int]:
+        conds = [Customer.company_id == company_id]
+        if kw := keyword.strip():
+            like = f"%{kw}%"
+            conds.append(or_(Customer.name.like(like), Customer.phone.like(like), Customer.address.like(like)))
+        where = *conds,
+        total = (await self.db.execute(select(func.count()).select_from(Customer).where(*where))).scalar_one()
+        stmt = (select(Customer).where(*where).order_by(Customer.id.desc())
+                .offset((page - 1) * page_size).limit(page_size))
+        return list((await self.db.execute(stmt)).scalars()), total
+
+    async def create(self, customer: Customer) -> Customer:
+        self.db.add(customer)
+        await self.db.flush()
+        return customer
+
+    async def delete(self, customer: Customer) -> None:
+        await self.db.delete(customer)