Trader: Add automatic sell before market close and profit/loss limits

[konard]

Summary

This PR implements the features requested in issue #202:

• Automatic sell before market close: Optional feature that can be enabled via configuration to automatically sell all positions before the market closes
• Profit/loss limits during sell: Ability to set maximum profit and loss percentages that trigger automatic sells when reached

Key Features

1. Auto-sell before market close

• New EnableAutoSellBeforeMarketClose boolean setting (default: false)
• New AutoSellMarketCloseTime setting to specify when to trigger auto-sell (format: "HH:mm:ss")
• When enabled, the bot will sell all positions at the current bid price to ensure execution before market close

2. Profit/Loss limits

• New MaxProfitPercent setting (optional, nullable decimal) - triggers sell when profit reaches this percentage
• New MaxLossPercent setting (optional, nullable decimal) - triggers sell when loss reaches this percentage
• Profit/loss calculation based on purchase price vs current bid price

3. Configuration flexibility

• Both features are optional and can be independently enabled/disabled
• Updated existing configuration files with examples
• TMON configuration has features disabled by default
• TRUR configuration demonstrates enabled features with reasonable limits

Implementation details

• Added new properties to TradingSettings class
• Enhanced TradingService with helper methods for checking conditions
• Integrated checks into both no-active-orders and active-sell-orders scenarios
• Uses bid price for emergency sells to ensure quick execution
• Comprehensive logging for all new functionality

Test plan

• Code compiles without errors
• Build succeeds with existing warnings (not related to new features)
• Configuration files are valid JSON
• New settings are properly logged on startup
• Example files demonstrate proper usage
• Both optional features can be disabled independently

Files changed

• TradingSettings.cs: Added new configuration properties
• TradingService.cs: Implemented auto-sell logic and profit/loss checking
• appsettings.TMON.json: Updated with disabled features as example
• appsettings.TRUR.json: Updated with enabled features as example
• examples/: Added example configuration and test files

🤖 Generated with Claude Code

---

Resolves #202