feat(lotto): briefing API 4계층 picks + tier_rationale 수용

lotto/app/routers/briefing.py

@@ -7,10 +7,24 @@ from .. import db
 router = APIRouter(prefix="/api/lotto")
 
 
+class TierRationale(BaseModel):
+    bonus: str = ""
+    extended: str = ""
+    pool: str = ""
+
+
+class BriefingPicks(BaseModel):
+    core: List[Dict[str, Any]] = Field(default_factory=list)
+    bonus: List[Dict[str, Any]] = Field(default_factory=list)
+    extended: List[Dict[str, Any]] = Field(default_factory=list)
+    pool: List[Dict[str, Any]] = Field(default_factory=list)
+
+
 class BriefingRequest(BaseModel):
     draw_no: int
-    picks: List[Dict[str, Any]]
+    picks: BriefingPicks
     narrative: Dict[str, Any]
+    tier_rationale: TierRationale = Field(default_factory=TierRationale)
     confidence: int = Field(ge=0, le=100)
     model: str
     tokens_input: int = 0