fix+feat: 修复工作台接口不存在 + 3D 区域分配制重建

- 补齐公告后端: Announcement 模型 + /api/announcements + 种子公告
  (修复工作台/布局页调用不存在接口报'接口不存在')
- 修复 seed init_db 前置模型导入(announcements 表未建)
- WindoorThreed 区域分配制: 每个重放区域唯一归属
  (扇认领重叠最大区域, 其余静态玻璃), 杜绝扇面板与玻璃重叠混乱
- 全区域薄框线还原真实窗格, 扇面板含玻璃+四边扇框

src/huamenchuang/api/platform.py

@@ -210,3 +210,17 @@ async def list_articles(db: DbSession, category: str | None = None):
     items = list((await db.execute(stmt)).scalars())
     return ok(data=[{"id": a.id, "title": a.title, "category": a.category, "content": a.content}
                     for a in items])
+
+
+# ---------------- 平台公告 ----------------
+
+@router.get("/announcements")
+async def list_announcements(db: DbSession):
+    """平台公告（工作台轮播 + 顶栏气泡）。"""
+    from huamenchuang.models.announcement import Announcement
+    stmt = select(Announcement).order_by(Announcement.sort, Announcement.id.desc())
+    items = list((await db.execute(stmt)).scalars())
+    return ok(data=[{
+        "id": a.id, "name": a.name, "desc": a.desc, "content": a.content,
+        "pic_url": a.pic_url, "created_at": str(a.created_at),
+    } for a in items])

src/huamenchuang/models/__init__.py

@@ -1,4 +1,5 @@
 """ORM 模型统一导出。"""
+from huamenchuang.models.announcement import Announcement
 from huamenchuang.models.business import (
     AfterSale,
     MeasureOrder,
@@ -19,6 +20,7 @@ from huamenchuang.models.windoor_template import WindoorCatelog, WindoorTemplate
 
 __all__ = [
     "AfterSale",
+    "Announcement",
     "Contract",
     "Customer",
     "DEFAULT_PROCESSES",

src/huamenchuang/models/announcement.py

@@ -0,0 +1,19 @@
+"""平台公告模型。"""
+import datetime
+
+from sqlalchemy import DateTime, String, Text
+from sqlalchemy.orm import Mapped, mapped_column
+
+from huamenchuang.core.database import Base
+
+
+class Announcement(Base):
+    __tablename__ = "announcements"
+
+    id: Mapped[int] = mapped_column(primary_key=True, autoincrement=True)
+    name: Mapped[str] = mapped_column(String(128))
+    desc: Mapped[str] = mapped_column(String(255), default="")
+    content: Mapped[str] = mapped_column(Text, default="")
+    pic_url: Mapped[str] = mapped_column(String(255), default="")
+    sort: Mapped[int] = mapped_column(default=0)
+    created_at: Mapped[datetime.datetime] = mapped_column(DateTime, default=datetime.datetime.utcnow)

src/huamenchuang/scripts/seed.py

@@ -11,6 +11,7 @@ DATA = Path(__file__).resolve().parents[3] / "data"
 
 
 async def seed() -> None:
+    import huamenchuang.models  # noqa: F401  确保全部模型注册到 metadata 后再建表
     from huamenchuang.core.database import SessionLocal, init_db
     from huamenchuang.models.user import User
     from huamenchuang.models.windoor_template import WindoorCatelog, WindoorTemplate
@@ -82,6 +83,22 @@ async def seed() -> None:
         await db.commit()
     print("帮助文章就绪")
 
+    # 5) 平台公告（幂等：按名称去重）
+    async with SessionLocal() as db:
+        from huamenchuang.models.announcement import Announcement
+        ANNOUNCEMENTS = [
+            ("AI 炫图功能上线", "选择样板一键生成多风格效果图，支持日景/黄昏/夜景与四种装修风格", 1),
+            ("样板组合工场发布", "拖拽组合多个窗型样板，自由摆放、等高对齐、边缘吸附，支持 3D 预览", 2),
+            ("3D 门窗开合演示", "3D 展示支持平开扇旋转、推拉扇滑动动画，可调节开合度", 3),
+            ("优化下料引擎", "合同级汇总算料需求，一维优化切割提升型材利用率", 4),
+        ]
+        existing = {n for (n,) in (await db.execute(select(Announcement.name))).all()}
+        for name, desc, sort in ANNOUNCEMENTS:
+            if name not in existing:
+                db.add(Announcement(name=name, desc=desc, sort=sort))
+        await db.commit()
+    print("平台公告就绪")
+
 
 if __name__ == "__main__":
     asyncio.run(seed())