Refactoring Fraction Lifecycle Management System

[eguguchkin]

Problem

The current fraction management implementation uses a proxy wrapper with mutex for safe access to the changing list of fractions. This approach does not scale for planned compaction and partitioning features where:

• Multiple fractions can merge into one
• One fraction can split into several
• Fraction lifecycle becomes more complex and doesn't fit the current model

Task

Replace the current proxy wrapper system with a fraction snapshots mechanism using reference counting via wait group.

Proposed Solution

1. Fraction Snapshots: Create a snapshot of the fraction list whenever its composition changes
2. Reference Counting: Use wait group to track active uses of fractions
3. Safe Deletion: Guarantee that a fraction won't be deleted while it's being used by someone