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/models/__init__.py

@@ -4,6 +4,7 @@ from app.models.boss_result import BossResult
 from app.models.encounter import Encounter
 from app.models.evolution import Evolution
 from app.models.game import Game
+from app.models.genlocke import Genlocke, GenlockeLeg
 from app.models.nuzlocke_run import NuzlockeRun
 from app.models.pokemon import Pokemon
 from app.models.route import Route
@@ -17,6 +18,8 @@ __all__ = [
     "Encounter",
     "Evolution",
     "Game",
+    "Genlocke",
+    "GenlockeLeg",
     "NuzlockeRun",
     "Pokemon",
     "Route",