feat(linkage): 移动改为任意入口位置选择，仅上卷鞍座触发生产

- 计划新增 position 字段；新增 /plan/{id}/move?position=… 与 /plan/positions/all
- line_service.place_at_position：放到任意位置(位置唯一占用)，上卷鞍座单独触发生产联动
- 入口跟踪：新增入口位置图(单一鞍座)显示占位；移动按钮弹出位置选择框
- 计划管理：移动按钮同样弹出位置选择框

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

backend/app/api/plan.py

@@ -142,6 +142,28 @@ async def move_to_saddle(plan_id: int, db: AsyncSession = Depends(get_db), _ = D
     return Response.ok(PlanOut.model_validate(plan))
 
 
+@router.get("/positions/all", response_model=Response[list[str]])
+async def list_positions(_ = Depends(get_current_user)):
+    """可移动到的入口位置列表（含唯一上卷鞍座）。"""
+    return Response.ok(line_service.ENTRY_POSITIONS)
+
+
+@router.patch("/{plan_id}/move", response_model=Response[PlanOut])
+async def move_plan(plan_id: int, position: str = Query(...), db: AsyncSession = Depends(get_db), _ = Depends(get_current_user)):
+    """移动：把计划放到所选入口位置；放到上卷鞍座才触发生产联动。"""
+    result = await db.execute(select(ProductionPlan).where(ProductionPlan.id == plan_id))
+    plan = result.scalar_one_or_none()
+    if not plan:
+        raise HTTPException(status_code=404, detail="计划不存在")
+    try:
+        await line_service.place_at_position(db, plan, position)
+    except ValueError as e:
+        raise HTTPException(status_code=400, detail=str(e))
+    await db.flush()
+    await db.refresh(plan)
+    return Response.ok(PlanOut.model_validate(plan))
+
+
 @router.patch("/{plan_id}/commit", response_model=Response[PlanOut])
 async def commit_producing(plan_id: int, db: AsyncSession = Depends(get_db), _ = Depends(get_current_user)):
     """投入生产：把鞍座上的计划置为生产中（兜底未实时变化的数据）。"""

backend/app/database.py

@@ -59,7 +59,8 @@ async def _run_migrations(conn):
         "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS incoming_weight DOUBLE PRECISION",
         "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS incoming_od DOUBLE PRECISION",
         "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS split_weights JSONB",
-        # 上卷鞍座 / 生产联动字段
+        # 入口位置 / 上卷鞍座 / 生产联动字段
+        "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS position VARCHAR(30)",
         "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS on_saddle INTEGER DEFAULT 0",
         "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS saddle_at TIMESTAMP",
         "ALTER TABLE production_plans ADD COLUMN IF NOT EXISTS run_started_at TIMESTAMP",

backend/app/models/plan.py

@@ -35,7 +35,8 @@ class ProductionPlan(Base):
     incoming_od = Column(Float, comment="来料外径 mm")
     split_weights = Column(JSON, comment="分卷重量 [t,...]")
 
-    # 上卷鞍座 / 生产联动
+    # 入口位置 / 上卷鞍座 / 生产联动
+    position = Column(String(30), comment="当前入口位置（上卷小车/称重位/地辊/倒卷小车/上卷鞍座）")
     on_saddle = Column(Integer, default=0, comment="是否在上卷鞍座 0/1")
     saddle_at = Column(DateTime, comment="移动到鞍座时间")
     run_started_at = Column(DateTime, comment="投入生产(有速度)时间")

backend/app/schemas/plan.py

@@ -78,7 +78,8 @@ class PlanOut(BaseModel):
     remark: Optional[str] = None
     created_by: Optional[str] = None
     created_at: datetime
-    # 上卷鞍座 / 生产联动
+    # 入口位置 / 上卷鞍座 / 生产联动
+    position: Optional[str] = None
     on_saddle: Optional[int] = 0
     saddle_at: Optional[datetime] = None
     run_started_at: Optional[datetime] = None

backend/app/services/line_service.py

@@ -17,12 +17,45 @@ from app.models.production import ProductionRecord
 from app.models.downtime import DowntimeRecord
 from app.models.line_state import LineState
 
+# ── 入口位置 ──
+SADDLE_NAME = "上卷鞍座"        # 唯一会触发生产联动的位置
+ENTRY_POSITIONS = [
+    "1#上卷小车", "2#上卷小车",
+    "1#称重位", "2#称重位",
+    "1#地辊", "2#地辊",
+    "1#倒卷小车", "2#倒卷小车",
+    SADDLE_NAME,
+]
+
 # ── 仿真参数 ──
 TARGET_LENGTH_M = 2000.0       # 带头目标长度（生产完成阈值）
 SIM_SPEED_M_MIN = 600.0        # 仿真线速度 m/min（2000m ≈ 200s）
 DOWNTIME_THRESHOLD_S = 600      # 速度为0持续超过该秒数判定停机（10min）
 
 
+async def place_at_position(db: AsyncSession, plan: ProductionPlan, position: str):
+    """把计划放到任意入口位置；位置唯一占用。上卷鞍座单独触发生产联动。"""
+    if position not in ENTRY_POSITIONS:
+        raise ValueError("未知入口位置")
+    if position == SADDLE_NAME:
+        await move_to_saddle(db, plan)
+        return
+    # 普通位置：清除同位置上的其它计划，移出鞍座（若在）
+    res = await db.execute(
+        select(ProductionPlan).where(ProductionPlan.position == position, ProductionPlan.id != plan.id)
+    )
+    for o in res.scalars():
+        o.position = None
+    plan.on_saddle = 0
+    plan.run_started_at = None
+    plan.run_speed = 0
+    plan.run_length_m = 0
+    plan.position = position
+    if plan.status == "producing":
+        plan.status = "online"
+    await ensure_online(db)
+
+
 def _shift_of(dt: datetime) -> str:
     return "甲" if 8 <= dt.hour < 20 else "乙"
 
@@ -60,6 +93,7 @@ async def move_to_saddle(db: AsyncSession, plan: ProductionPlan):
     if occupied and occupied.id != plan.id:
         raise ValueError("上卷鞍座已被占用，请等待当前钢卷生产完成")
     plan.on_saddle = 1
+    plan.position = SADDLE_NAME
     plan.saddle_at = datetime.now()
     plan.run_started_at = None
     plan.run_speed = 0
@@ -86,6 +120,7 @@ async def _produce(db: AsyncSession, plan: ProductionPlan):
     plan.status = "produced"
     plan.produced_at = now
     plan.on_saddle = 0
+    plan.position = None
     plan.run_speed = 0
     plan.run_length_m = TARGET_LENGTH_M