feat: add auth system, boss pokemon details, moves/abilities API, and run ownership

Add user authentication with login/signup/protected routes, boss pokemon
detail fields and result team tracking, moves and abilities selector
components and API, run ownership and visibility controls, and various
UI improvements across encounters, run list, and journal pages.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

backend/scripts/assign_unowned_runs.py

@@ -0,0 +1,81 @@
+#!/usr/bin/env python3
+"""Assign existing unowned runs to a user.
+
+Usage:
+    cd backend && uv run python scripts/assign_unowned_runs.py <user_uuid>
+
+This script assigns all runs without an owner to the specified user.
+Useful for migrating existing data after implementing user ownership.
+"""
+
+import asyncio
+import sys
+from uuid import UUID
+
+from sqlalchemy import select, update
+
+sys.path.insert(0, "src")
+
+from app.core.database import async_session  # noqa: E402
+from app.models.nuzlocke_run import NuzlockeRun  # noqa: E402
+from app.models.user import User  # noqa: E402
+
+
+async def main(user_uuid: str) -> None:
+    try:
+        user_id = UUID(user_uuid)
+    except ValueError:
+        print(f"Error: Invalid UUID format: {user_uuid}")
+        sys.exit(1)
+
+    async with async_session() as session:
+        # Verify user exists
+        user_result = await session.execute(select(User).where(User.id == user_id))
+        user = user_result.scalar_one_or_none()
+        if user is None:
+            print(f"Error: User {user_id} not found")
+            sys.exit(1)
+
+        print(f"Found user: {user.email} (display_name: {user.display_name})")
+
+        # Count unowned runs
+        count_result = await session.execute(
+            select(NuzlockeRun.id, NuzlockeRun.name).where(
+                NuzlockeRun.owner_id.is_(None)
+            )
+        )
+        unowned_runs = count_result.all()
+
+        if not unowned_runs:
+            print("No unowned runs found.")
+            return
+
+        print(f"\nFound {len(unowned_runs)} unowned run(s):")
+        for run_id, run_name in unowned_runs:
+            print(f"  - [{run_id}] {run_name}")
+
+        # Confirm action
+        confirm = input(f"\nAssign all {len(unowned_runs)} runs to this user? [y/N] ")
+        if confirm.lower() != "y":
+            print("Aborted.")
+            return
+
+        # Perform the update
+        await session.execute(
+            update(NuzlockeRun)
+            .where(NuzlockeRun.owner_id.is_(None))
+            .values(owner_id=user_id)
+        )
+        await session.commit()
+
+        print(f"\nAssigned {len(unowned_runs)} run(s) to user {user.email}")
+
+
+if __name__ == "__main__":
+    if len(sys.argv) != 2:
+        print("Usage: python scripts/assign_unowned_runs.py <user_uuid>")
+        print("\nExample:")
+        print("  uv run python scripts/assign_unowned_runs.py 550e8400-e29b-41d4-a716-446655440000")
+        sys.exit(1)
+
+    asyncio.run(main(sys.argv[1]))