Allow GitHub bot to load repository code to Doublets store on default branch commits

[konard]

Summary

• Implemented a CommitTracker that monitors commits to default branches of organization repositories
• Created LoadRepositoryCodeToDoubletsTrigger that automatically loads repository code into the Doublets store when new commits are detected
• Extended GitHubStorage with methods to retrieve repository contents from GitHub API
• Integrated the new functionality into the main bot loop in Program.cs

Key Features

• Automatic code loading: Each commit to default branch triggers code snapshot update in the links store
• File filtering: Skips binary files and large files (>1MB) to optimize storage
• Recursive directory processing: Loads entire repository structure
• File set organization: Code is organized by repository in named file sets (e.g., "linksplatform/Bot")
• Error handling: Graceful handling of repository access issues and file processing errors

Technical Implementation

The solution follows the existing bot architecture patterns:

• CommitTracker implements ITracker<GitHubCommit> and polls for recent commits
• LoadRepositoryCodeToDoubletsTrigger implements ITrigger<GitHubCommit> and processes each commit
• Repository content is stored in the Doublets store using the existing FileStorage abstraction
• Integration with existing GitHub API wrappers in GitHubStorage

Test Plan

• Build verification - solution compiles without errors
• Unit test - created test script to verify Doublets storage functionality
• Integration ready - new tracker is integrated into main bot loop

The implementation is ready for deployment and will start loading repository code snapshots on the next bot cycle after merge.

🤖 Generated with Claude Code

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Resolves #76