Implement Hint Marketplace and Trading Contract

[Samuel1505]

Implement Hint Marketplace and Trading Contract

Summary

This PR implements a complete hint marketplace contract that enables players to create, buy, sell, and trade puzzle hints with dynamic pricing, quality ratings, creator royalties, and bundle support.

Changes

• Added new hint_marketplace contract with full marketplace functionality
• Implemented dynamic pricing algorithm based on quality and demand
• Added escrow mechanism for secure buy/sell transactions
• Implemented quality rating system with automatic quality updates
• Added creator royalty distribution on all sales
• Implemented hint pack bundles with discount pricing
• Added listing expiration logic with automatic cleanup
• Comprehensive test suite with 15+ test cases

Features

1. Hint Management: Create hints with quality ratings and list them for sale
2. Dynamic Pricing: Prices adjust based on hint quality and market demand
3. Secure Transactions: Escrow-based buy/sell with automatic fund distribution
4. Quality Ratings: Users can rate hints, affecting quality and pricing
5. Royalties: Automatic royalty payments to hint creators
6. Bundles: Create and purchase hint packs at discounted prices
7. Expiration: Configurable listing expiration with automatic cleanup

Testing

All tests pass. The implementation includes:

• Unit tests for core functionality
• Integration tests for complete workflows
• Edge case testing
• Error condition validation

Acceptance Criteria

• Hints listed and tradable
• Pricing adjusts based on demand
• Escrow holds funds securely
• Royalties paid to creators
• Bundles work correctly
• Listing expiration implemented

Files Changed

• contracts/hint_marketplace/Cargo.toml (new)
• contracts/hint_marketplace/src/lib.rs (new, ~1000 lines)
• contracts/hint_marketplace/src/test.rs (new, ~650 lines)
• Cargo.toml (added hint_marketplace to workspace)

Related Issue

Closes #17

[Samuel1505]

hello @Mkalbani kindly review this PR

[Samuel1505]

hello @Mkalbani kindly review and merge this pr