Add Default State After Grace Period Expires

[mikewheeleer]

Implement Default or Workout State Machine Branch

Description

Define behavior when invoice repayment is overdue beyond grace: transition to a default state, block SME withdrawal of new liquidity where appropriate, and enable documented recovery or refund paths.

Requirements and context

• Must be secure, tested, and documented
• Should be efficient and easy to review

Suggested execution

• Fork the repo and create a branch
• git checkout -b feature/escrow-default-state-machine
• Implement changes
• Write contract: escrow/src/lib.rs
• Write comprehensive tests: escrow/src/test.rs
• Add documentation: README.md
• Include Rust doc comments for default triggers and reversibility
• Validate assumptions on fairness between SME and investors

Test and commit

• Run tests
• Cover edge cases
• Include test output and security notes

Example commit message

feat(escrow): add default state after grace with documented recovery paths

Guidelines

• Minimum 95 percent test coverage
• Clear documentation
• Timeframe: 96 hours

[HushLuxe]

@HushLuxe has applied to work on this issue as part of the Stellar Wave Program's 3rd wave.

I will like to work on this

ℹ️ Repo Maintainers: To accept this application, review their application or assign @HushLuxe to this issue.