debt(D2): 统一预测结果类型为 PredictResult,路由去 dict 分支

- PredictResult 扩展可选字段 mode/agent_outputs/agent_weights/prompt_tokens/completion_tokens
- MultiPredictResult 变为 PredictResult 别名(保留 R4 守卫标记与 re-export)
- baseline 改返回 PredictResult(修复 backtest 对 baseline AttributeError 的潜伏 bug)
- 预测路由单一属性映射,删除全部 isinstance(result, dict) 分支
- _persist_baseline 属性化,baseline upsert 语义不变(prompt_version/token/latency 同前)
- TDD: 5 新测试 + test_baseline.py 属性化;全量 257 passed

src/llm/baseline.py

@@ -12,6 +12,7 @@ from sqlalchemy import case, func, select
 
 from src.db.base import AsyncSession, AsyncSessionLocal
 from src.db.models import Match
+from src.llm.predict import PredictResult
 
 logger = logging.getLogger(__name__)
 
@@ -52,11 +53,13 @@ async def predict_baseline(
     *,
     backtest: bool = False,
     cutoff_at: datetime | None = None,
-) -> dict:
+) -> PredictResult:
     """极简基线预测:主场场均进球 vs 客场场均进球。
 
-    返回与 PredictResult 兼容的字典:
+    返回 PredictResult(D2 统一结果类型):
       provider=model="baseline", 不调用 LLM,latency_ms≈0。
+    prediction_id 为占位 0 —— baseline 不在服务层落库,
+    由路由层 _persist_baseline 落库后取得真实 id。
     """
     async with AsyncSessionLocal() as db:
         match = await db.get(Match, match_id)
@@ -90,24 +93,26 @@ async def predict_baseline(
     else:
         pred_1x2 = "X"
 
-    return {
-        "pred_home_goals": float(pred_home),
-        "pred_away_goals": float(pred_away),
-        "alt_pred_home_goals": None,
-        "alt_pred_away_goals": None,
-        "pred_1x2": pred_1x2,
-        "subjective_confidence": 0.5,
-        "prompt_tokens": 0,
-        "completion_tokens": 0,
-        "reasoning": (
+    return PredictResult(
+        prediction_id=0,  # 占位:真实 id 由路由层 _persist_baseline 落库后返回
+        provider="baseline",
+        model="baseline",
+        prompt_version="baseline_v1",
+        mode="baseline",
+        pred_home_goals=float(pred_home),
+        pred_away_goals=float(pred_away),
+        alt_pred_home_goals=None,
+        alt_pred_away_goals=None,
+        pred_1x2=pred_1x2,
+        subjective_confidence=0.5,
+        reasoning=(
             f"基线估计(非投注建议): 主队主场场均进球 {home_avg:.2f} → 预测 {pred_home}; "
             f"客队客场场均进球 {away_avg:.2f} → 预测 {pred_away}。"
         ),
-        "provider": "baseline",
-        "model": "baseline",
-        "prompt_version": "baseline_v1",
-        "mode": "baseline",
-        "status": "success",
-        "latency_ms": 0,
-        "raw": {"home_avg": round(home_avg, 2), "away_avg": round(away_avg, 2)},
-    }
+        context="",  # baseline 不构建 LLM 上下文
+        status="success",
+        latency_ms=0,
+        prompt_tokens=0,
+        completion_tokens=0,
+        raw={"home_avg": round(home_avg, 2), "away_avg": round(away_avg, 2)},
+    )