feat: 新增题图上传接口和排播接口

backend/app/api/schedules.py

@@ -0,0 +1,70 @@
+"""
+排期 API — 查询未来排播计划
+
+降级逻辑：
+- schedules 表有数据 → 从 schedules 取未来 limit 条 JOIN episodes
+- schedules 表无数据 → 从 episodes 表取最近 limit 期待播期次（air_date 升序）
+"""
+
+from fastapi import APIRouter, Depends
+from sqlmodel import Session, select
+
+from app.core.deps import get_current_user
+from app.db.session import get_session
+from app.models.user import User
+from app.models.episode import Episode
+from app.models.schedule import Schedule
+
+router = APIRouter(prefix="/api/schedules", tags=["排期"])
+
+
+@router.get("/upcoming")
+def list_upcoming_schedules(
+    limit: int = 6,
+    session: Session = Depends(get_session),
+    current_user: User = Depends(get_current_user),
+):
+    """获取未来排播计划（三角色均可读）。
+    
+    优先从 schedules 表取，schedules 无数据时降级取 episodes 最近待播期次。
+    """
+    # 先查 schedules
+    statement = (
+        select(Schedule, Episode)
+        .join(Episode, Schedule.episode_id == Episode.id, isouter=True)
+        .where(Schedule.planned_air_date >= Episode.air_date)
+        .order_by(Schedule.planned_air_date.asc())
+        .limit(limit)
+    )
+    results = session.exec(statement).all()
+
+    # 降级：从 episodes 直接取（当 schedules 为空或不足时）
+    if not results or len(results) < limit:
+        fallback_stmt = (
+            select(Episode)
+            .order_by(Episode.air_date.asc())
+            .limit(limit)
+        )
+        episodes = session.exec(fallback_stmt).all()
+        return [
+            {
+                "episode_number": ep.episode_number,
+                "program_name": ep.program_name,
+                "planned_air_date": str(ep.air_date),
+                "editor_name_snapshot": ep.editor_name_snapshot,
+            }
+            for ep in episodes
+        ]
+
+    # schedules 有数据
+    output = []
+    for schedule, episode in results:
+        if episode is None:
+            continue
+        output.append({
+            "episode_number": episode.episode_number,
+            "program_name": episode.program_name,
+            "planned_air_date": str(schedule.planned_air_date),
+            "editor_name_snapshot": episode.editor_name_snapshot,
+        })
+    return output