Full app rebuild: FastAPI backend + React Native mobile with auth, championships, admin

Backend (FastAPI + SQLAlchemy + SQLite):
- JWT auth with access/refresh tokens, bcrypt password hashing
- User model with member/organizer/admin roles, auto-approve members
- Championship, Registration, ParticipantList, Notification models
- Alembic async migrations, seed data with test users
- Registration endpoint returns tokens for members, pending for organizers
- /registrations/my returns championship title/date/location via eager loading
- Admin endpoints: list users, approve/reject organizers

Mobile (React Native + Expo + TypeScript):
- Zustand auth store, Axios client with token refresh interceptor
- Role-based registration (Member vs Organizer) with contextual form labels
- Tab navigation with Ionicons, safe area headers, admin tab for admin role
- Championships list with status badges, detail screen with registration progress
- My Registrations with championship title, progress bar, and tap-to-navigate
- Admin panel with pending/all filter, approve/reject with confirmation
- Profile screen with role badge, Ionicons info rows, sign out
- Password visibility toggle (Ionicons), keyboard flow hints (returnKeyType)

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

backend/app/models/participant.py

@@ -0,0 +1,25 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import Boolean, DateTime, ForeignKey, Text, Uuid, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class ParticipantList(Base):
+    __tablename__ = "participant_lists"
+
+    id: Mapped[uuid.UUID] = mapped_column(Uuid(as_uuid=True), primary_key=True, default=uuid.uuid4)
+    championship_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("championships.id", ondelete="CASCADE"), nullable=False, unique=True
+    )
+    published_by: Mapped[uuid.UUID | None] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("users.id", ondelete="SET NULL")
+    )
+    is_published: Mapped[bool] = mapped_column(Boolean, default=False)
+    published_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+    notes: Mapped[str | None] = mapped_column(Text)
+    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+
+    championship: Mapped["Championship"] = relationship(back_populates="participant_list")  # type: ignore[name-defined]