Fix Python 3.9 compatibility issues

Resolved startup errors:

1. Type hint compatibility:
   - Changed SkaterStatsDTO | GoalieStatsDTO to Union[SkaterStatsDTO, GoalieStatsDTO]
   - Python 3.9 does not support | operator for type unions

2. Yahoo Fantasy adapter import:
   - Made yfpy import lazy in get_fantasy_repository()
   - Prevents ModuleNotFoundError when yfpy not installed
   - Only loads Yahoo adapter when actually needed

3. Updated startup script for compatibility

The application now starts successfully on Python 3.9.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

src/application/dto/player_dto.py

@@ -1,5 +1,5 @@
 """Player Data Transfer Objects."""
-from typing import Optional
+from typing import Optional, Union
 from pydantic import BaseModel
 
 
@@ -59,5 +59,5 @@ class PlayerWithStatsDTO(BaseModel):
     """Combined player information and statistics."""
 
     player: PlayerDTO
-    stats: Optional[SkaterStatsDTO | GoalieStatsDTO]
+    stats: Optional[Union[SkaterStatsDTO, GoalieStatsDTO]]
     stats_type: str  # "skater", "goalie", or "none"

src/presentation/api/dependencies.py

@@ -3,7 +3,6 @@ from functools import lru_cache
 
 from src.domain.repositories import PlayerRepository, TeamRepository, FantasyRepository
 from src.infrastructure.adapters.nhl import NHLPlayerAdapter, NHLTeamAdapter
-from src.infrastructure.adapters.yahoo_fantasy import YahooFantasyAdapter
 from src.infrastructure.config import Settings, get_settings
 
 
@@ -40,6 +39,9 @@ def get_fantasy_repository() -> FantasyRepository:
     This function can be modified to return different implementations
     without changing any business logic or API code.
     """
+    # Lazy import to avoid requiring yfpy until actually needed
+    from src.infrastructure.adapters.yahoo_fantasy import YahooFantasyAdapter
+
     settings = get_cached_settings()
     return YahooFantasyAdapter(
         consumer_key=settings.yahoo_consumer_key,

start_server.sh

@@ -0,0 +1,18 @@
+#!/bin/bash
+# Startup script for Project Kempe Fantasy Hockey Backend
+
+cd "$(dirname "$0")"
+
+echo "=========================================="
+echo "Project Kempe - Fantasy Hockey Backend"
+echo "=========================================="
+echo ""
+echo "Starting FastAPI server..."
+echo "Server will be available at: http://localhost:8000"
+echo "API Documentation: http://localhost:8000/docs"
+echo ""
+echo "Press Ctrl+C to stop the server"
+echo ""
+
+# Start the server using python module
+python3 -m uvicorn src.presentation.api.main:app --reload --host 0.0.0.0 --port 8000