Implement friend recommendations based on shared programming languages

[konard]

Summary

• ✅ Implemented new "friends" command that recommends users based on shared programming languages
• ✅ Added support for Russian and English command variants ("друзья", "friends", "рекомендации", "recommendations")
• ✅ Developed algorithm that sorts recommendations by number of shared languages then by karma
• ✅ Added comprehensive message formatting with shared languages display
• ✅ Included message length truncation for VK API limits
• ✅ Added unit tests for the new functionality

Technical Implementation

New Command Pattern

Added FRIENDS_RECOMMENDATIONS pattern in python/patterns.py that accepts:

• "друзья" / "friends"
• "рекомендации" / "recommendations"
• Optional number parameter to limit results (default: 10)

Algorithm Logic

1. Gets current user's programming languages
2. Searches all users in the chat for shared programming languages
3. Calculates compatibility score based on number of shared languages
4. Sorts by shared language count (descending), then by karma (descending)
5. Returns formatted recommendations with shared languages highlighted

Files Modified

• python/patterns.py: Added FRIENDS_RECOMMENDATIONS pattern
• python/modules/commands.py: Implemented friends_recommendations method
• python/modules/commands_builder.py: Added build_friends_recommendations method
• python/__main__.py: Registered the new command
• python/tests.py: Added unit tests
• experiments/test_friend_recommendations.py: Added standalone test suite

Test Plan

• Syntax validation of all modified Python files
• Unit tests added to existing test suite
• Algorithm logic verified with standalone test script
• Message formatting and truncation tested
• Edge cases handled (no languages, no matches, etc.)

Usage Examples

друзья           # Get top 10 friend recommendations
friends 5        # Get top 5 friend recommendations  
рекомендации 3   # Get top 3 friend recommendations
recommendations  # Get top 10 friend recommendations

Sample Output

🤝 Рекомендации друзей (ваши языки: JavaScript, Python):

1. [id123|Иван] (karma: 50) - github.com/ivan - общие: Python, JavaScript (2)
2. [id456|Мария] (karma: 30) - общие: Python (1)
3. [id789|Петр] (karma: 25) - github.com/peter - общие: JavaScript (1)

Fixes #60

🤖 Generated with Claude Code