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/registration.py

@@ -0,0 +1,36 @@
+import uuid
+from datetime import datetime
+
+from sqlalchemy import DateTime, ForeignKey, String, Text, UniqueConstraint, Uuid, func
+from sqlalchemy.orm import Mapped, mapped_column, relationship
+
+from app.database import Base
+
+
+class Registration(Base):
+    __tablename__ = "registrations"
+    __table_args__ = (UniqueConstraint("championship_id", "user_id", name="uq_registration_champ_user"),)
+
+    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
+    )
+    user_id: Mapped[uuid.UUID] = mapped_column(
+        Uuid(as_uuid=True), ForeignKey("users.id", ondelete="CASCADE"), nullable=False
+    )
+    category: Mapped[str | None] = mapped_column(String(255))
+    level: Mapped[str | None] = mapped_column(String(100))
+    notes: Mapped[str | None] = mapped_column(Text)
+
+    # Multi-stage status:
+    # 'submitted' → 'form_submitted' → 'payment_pending' → 'payment_confirmed' →
+    # 'video_submitted' → 'accepted' | 'rejected' | 'waitlisted'
+    status: Mapped[str] = mapped_column(String(30), nullable=False, default="submitted")
+    video_url: Mapped[str | None] = mapped_column(String(2048))
+
+    submitted_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), server_default=func.now())
+    decided_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
+
+    championship: Mapped["Championship"] = relationship(back_populates="registrations")  # type: ignore[name-defined]
+    user: Mapped["User"] = relationship(back_populates="registrations")  # type: ignore[name-defined]
+    notification_logs: Mapped[list["NotificationLog"]] = relationship(back_populates="registration")  # type: ignore[name-defined]