Add comprehensive structured logging system

Features:
- JSON-formatted logs for easy parsing and analysis
- Rotating log files (prevents disk space issues)
  * ajarbot.log: All events, 10MB rotation, 5 backups
  * errors.log: Errors only, 5MB rotation, 3 backups
  * tools.log: Tool execution tracking, 10MB rotation, 3 backups

Tool Execution Tracking:
- Every tool call logged with inputs, outputs, duration
- Success/failure status tracking
- Performance metrics (execution time in milliseconds)
- Error messages captured with full context

Logging Integration:
- tools.py: All tool executions automatically logged
- Structured logger classes with context preservation
- Console output (human-readable) + file logs (JSON)
- Separate error log for quick issue identification

Log Analysis:
- JSON format enables programmatic analysis
- Easy to search for patterns (max tokens, iterations, etc.)
- Performance tracking (slow tools, failure rates)
- Historical debugging with full context

Documentation:
- LOGGING.md: Complete usage guide
- Log analysis examples with jq commands
- Error pattern reference
- Maintenance and integration instructions

Benefits:
- Quick error diagnosis with separate errors.log
- Performance monitoring and optimization
- Historical analysis for troubleshooting
- Automatic log rotation (max 95MB total)

Updated .gitignore to exclude logs/ directory

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.gitignore

@@ -65,3 +65,4 @@ config/google_oauth_token.json
 
 # Logs
 *.log
+logs/