[GrantFox][High] Prove market settlement conservation

[greatest0fallt1me]

Summary

Prove market settlement conservation

Why this matters

Settlement must distribute the exact available value without double payment or stranded balances.

Scope

Define conservation equations and enforce them across winning, losing, void, and partial-liquidity outcomes.

Acceptance criteria

• Debits equal credits plus documented fees/remainders.
• Each market settles once.
• Void and partial outcomes conserve funds.
• Property tests cover minimum, maximum, and adversarial amounts.

Validation

Add regression coverage for existing behavior, failure modes, authorization boundaries, and compatibility. The implementation must pass the repository CI checks.

Non-goals

• Typo-only, formatting-only, or documentation-only changes.
• Unrelated refactors or dependency upgrades.
• Weakening existing security, authorization, CI, or production safeguards.

Contributor application

Before implementation, comment with relevant experience, a 1–4 bullet approach, and an estimate for opening the first draft PR. Wait for maintainer assignment before coding.

PR requirements

Use a feature branch, include Closes #<issue-number>, check every acceptance criterion, link criteria to code/tests, explain security and failure-mode considerations, and pass CI.

Reward-readiness

This is a substantive GrantFox campaign issue. Merge and CI success do not by themselves guarantee reward eligibility; final reward-readiness is determined by campaign review.

[safal207]

Hi — this is closely aligned with my recent independent escrow and settlement verification work.

Relevant experience:
I recently completed an escrow lifecycle assessment where state-transition analysis found a material funds-liveness issue that ordinary function-level tests had missed. My current focus is settlement conservation, replay safety, and lifecycle invariants.

Approach for #1375:

• define conservation equations for winning, losing, void, and partial-liquidity outcomes;
• verify each market settles exactly once;
• test minimum, maximum, repeated, and adversarial value cases;
• add regression/property coverage for double-payment and stranded-balance paths.

First draft PR: within 1 day after maintainer assignment.

I’ll wait for assignment before implementation.

[devyeyostellar]

Hello! I am highly interested in this bounty. My approach:

1. Review the existing liquidity pool and slippage logic.
2. Add the requested safety bounds and validation checks.
3. Expand the test suite to simulate extreme market conditions.
4. Submit a well-documented PR ready for deployment.