CLAUDE: Add playoff configuration constants for injury roll validation

Added constants to config.py to support playoff week validation:
- playoff_weeks_per_season: 3 (weeks 19-21)
- playoff_round_one_games: 5 (best of 5 series)
- playoff_round_two_games: 7 (best of 7 series)
- playoff_round_three_games: 7 (best of 7 series)

These constants are used in injury roll modals (views/modals.py) to:
1. Allow injury rolls during playoff weeks (extends max_week validation)
2. Validate game numbers based on playoff round (different series lengths)

Validation logic:
- Regular season (weeks 1-18): Max 4 games per week
- Playoff Round 1 (week 19): Max 5 games (best of 5)
- Playoff Round 2 (week 20): Max 7 games (best of 7)
- Playoff Round 3 (week 21): Max 7 games (best of 7)

This ensures injury rolls can be submitted with proper week/game validation
throughout the entire season including playoffs.

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

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

config.py

@@ -32,6 +32,10 @@ class BotConfig(BaseSettings):
     sba_color: str = "a6ce39"
     weeks_per_season: int = 18
     games_per_week: int = 4
+    playoff_weeks_per_season: int = 3
+    playoff_round_one_games: int = 5
+    playoff_round_two_games: int = 7
+    playoff_round_three_games: int = 7
     modern_stats_start_season: int = 8
     offseason_flag: bool = False  # When True, relaxes roster limits and disables weekly freeze/thaw