Document mathematical proofs

[secsovereign]

Description

Add inline documentation explaining mathematical invariants for functions with Kani proofs.

Context

We have 176+ Kani proofs in the codebase, but the mathematical reasoning behind them isn't always documented. Adding clear documentation will help contributors understand the formal verification approach.

Acceptance Criteria

• Identify functions with Kani proofs that lack documentation
• Add inline documentation explaining mathematical invariants
• Document the relationship between proofs and consensus rules
• Ensure documentation is clear and accessible

Technical Details

• Files to modify: src/**/*.rs (functions with Kani proofs)
• Dependencies: None
• References: See docs/FORMAL_VERIFICATION_PLAN.md for context

Skills Required

• Technical writing
• Bitcoin protocol knowledge
• Mathematical notation understanding

Difficulty

• Good First Issue
• Intermediate
• Advanced

Priority

• P0 (Critical - Blocks production)
• P1 (High - Important feature)
• P2 (Medium - Nice to have)
• P3 (Low - Future enhancement)

Getting Started

1. Search for #[cfg(kani)] or kani::proof in the codebase
2. Identify functions with proofs but minimal documentation
3. Add doc comments explaining the mathematical invariants
4. Reference related Orange Paper sections where applicable
5. Submit PR with documentation improvements