feat: replace --pretty with --output flag for flexible log control

[lox]

Replaces the boolean --pretty flag with an --output enum flag that supports three modes for better control over bot log output during testing.

Changes

New --output flag modes:

• logs: Show all bot logs (default, current behavior)
• bot-cmd: Show only custom bot logs from --bot-cmd, suppress built-in bot logs from --spec (useful for focusing on your bot's behavior)
• hand-history: Pretty hand visualization with all bot logs suppressed (replaces --pretty)

Implementation:

• Added QuietLogs field to BotSpec for per-bot log control
• Built-in bots are quieted in bot-cmd and hand-history modes
• Custom bots are only quieted in hand-history mode

Motivation

When testing custom bots against built-in opponents, the log output from all the pre-canned bots creates noise that makes it hard to focus on your bot's behavior. The bot-cmd mode solves this by showing only your custom bot's output while the built-in bots run silently.

Example Usage

# Focus on your bot's logs only
pokerforbots spawn \
  --spec "calling-station:3,aggressive:2" \
  --bot-cmd "./my-bot" \
  --output bot-cmd

# Watch hands with pretty visualization
pokerforbots spawn \
  --spec "complex:6" \
  --output hand-history

Testing

• ✅ All tests passing
• ✅ No race conditions
• ✅ Verified all three modes work correctly