Add genlocke creation wizard with backend API and 4-step frontend

Implements the genlocke creation feature end-to-end: Genlocke and
GenlockeLeg models with migration, POST /genlockes endpoint that
creates the genlocke with all legs and auto-starts the first run,
and a 4-step wizard UI (Name, Select Games with preset templates,
Rules, Confirm) at /genlockes/new.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

backend/src/app/schemas/genlocke.py

@@ -0,0 +1,30 @@
+from datetime import datetime
+
+from app.schemas.base import CamelModel
+from app.schemas.game import GameResponse
+
+
+class GenlockeCreate(CamelModel):
+    name: str
+    game_ids: list[int]
+    genlocke_rules: dict = {}
+    nuzlocke_rules: dict = {}
+
+
+class GenlockeLegResponse(CamelModel):
+    id: int
+    genlocke_id: int
+    game_id: int
+    run_id: int | None = None
+    leg_order: int
+    game: GameResponse
+
+
+class GenlockeResponse(CamelModel):
+    id: int
+    name: str
+    status: str
+    genlocke_rules: dict
+    nuzlocke_rules: dict
+    created_at: datetime
+    legs: list[GenlockeLegResponse] = []