feat(replay): M9-6 Bar Replay 线性重放（as_of 逐日仅用当时数据）

- domain/entities/replay.py：ReplayDay{top/events/counts}/ReplayResult 时间线
- ReplayService：universe.symbols 白名单必填（≤40）且重放交易日 ≤90（防全市场长任务）；
  每个交易日以 <=as_of 数据经同一 signal/score 引擎生成帧
- POST /api/replays（边界校验）→ 时间线；供前端 Bar Replay 控件（v3 §20.6 阶段二）
- tests/test_replays.py：重放帧 == 回测 selection_history 逐调仓日一致；范围约束；
  后段暴涨股不泄漏进早段帧（未来函数）；API 400/200；全量 pytest 通过

backend/app/api/deps.py

@@ -11,6 +11,7 @@ from fastapi import Depends
 from sqlalchemy.orm import Session
 
 from app.application.services.chart_service import ChartService
+from app.application.services.replay_service import ReplayService
 from app.application.services.selection_service import SelectionService
 from app.application.services.signal_service import SignalService
 from app.domain.repositories.composite import CompositeRepository
@@ -89,6 +90,13 @@ def _service_factory(
     return ResearchService(stock_repo, daily_repo, engine)
 
 
+def _replay_service_factory(
+    stock_repo: Annotated[StockRepository, Depends(_stock_repo_factory)],
+    daily_repo: Annotated[DailyBarRepository, Depends(_daily_repo_factory)],
+) -> ReplayService:
+    return ReplayService(stock_repo, daily_repo)
+
+
 def _signal_service_factory(
     stock_repo: Annotated[StockRepository, Depends(_stock_repo_factory)],
     daily_repo: Annotated[DailyBarRepository, Depends(_daily_repo_factory)],
@@ -135,6 +143,7 @@ FactorRepoDep = Annotated[FactorRepository, Depends(_factor_repo_factory)]
 CompositeRepoDep = Annotated[CompositeRepository, Depends(_composite_repo_factory)]
 SignalRepoDep = Annotated[SignalRepository, Depends(_signal_repo_factory)]
 SignalServiceDep = Annotated[SignalService, Depends(_signal_service_factory)]
+ReplayServiceDep = Annotated[ReplayService, Depends(_replay_service_factory)]
 ChartServiceDep = Annotated[ChartService, Depends(_chart_service_factory)]
 StrategyRepoDep = Annotated[StrategyRepository, Depends(_strategy_repo_factory)]
 

backend/app/api/replays.py

@@ -0,0 +1,33 @@
+"""Bar Replay API（M9-6）：POST /api/replays —— 线性重放选股/信号时间线。"""
+
+from __future__ import annotations
+
+from datetime import date
+
+from fastapi import APIRouter, HTTPException
+from pydantic import BaseModel, Field
+
+from app.api.deps import ReplayServiceDep
+from app.domain.entities.replay import ReplayResult
+from app.domain.entities.selection import SelectionQuery
+from app.domain.entities.signal import SignalRules
+
+router = APIRouter(prefix="/replays", tags=["replays"])
+
+
+class ReplayRequest(BaseModel):
+    query: SelectionQuery
+    rules: SignalRules = SignalRules()
+    start: date
+    end: date
+    top_n: int = Field(default=5, ge=1, le=20)
+
+
+@router.post("", response_model=ReplayResult, summary="线性重放（as_of 逐日，仅用当时数据）")
+def run_replay(req: ReplayRequest, service: ReplayServiceDep) -> ReplayResult:
+    if req.start >= req.end:
+        raise HTTPException(status_code=400, detail="start 必须早于 end")
+    try:
+        return service.replay(req.query, req.rules, req.start, req.end, req.top_n)
+    except ValueError as exc:
+        raise HTTPException(status_code=400, detail=str(exc)) from exc

backend/app/api/router.py

@@ -16,6 +16,7 @@ from app.api import (
     factors,
     health,
     jobs,
+    replays,
     research,
     selections,
     signals,
@@ -31,6 +32,7 @@ api_router.include_router(composites.router)
 api_router.include_router(research.router)
 api_router.include_router(selections.router)
 api_router.include_router(charts.router)
+api_router.include_router(replays.router)
 api_router.include_router(signals.router)
 api_router.include_router(strategies.router)
 api_router.include_router(jobs.router)