establish core Soroban contract architecture`

[Divineifed1]

Description:
Define the multi-contract package structure for the Renaissance platform. Currently only a single renaissance-contract counter crate exists. We need a monorepo layout to support the full product surface.

Proposed structure:

contracts/
├── Cargo.toml          # workspace root
├── core/
│   └── Cargo.toml      # shared types, errors, events
├── counter/
│   └── src/lib.rs      # starter (already scaffolded)
├── betting/
│   └── src/lib.rs      # TBD
├── rewards/
│   └── src/lib.rs      # TBD
└── player-nft/
    └── src/lib.rs      # TBD

Acceptance criteria:

• contracts/Cargo.toml workspace configured
• Each sub-crate builds independently via stellar contract build
• Shared core crate exports common Soroban types (Address, Symbol, errors)
• Cargo.lock committed and CI passes cargo check --all

[mijinummi]

Hello maintainers, I am a full stack developer experience in building scalable systems, very interested in web and mobile applications. I have confidence that i can deliver this perfectly

[gloskull]

Hi, I’d love to work on this issue. I have 4 years of experience across backend, frontend, full-stack, and smart contract development. I understand the task clearly and can deliver a clean, efficient, well-tested solution on time, with strong focus on code quality and maintainability. My PR will be submitted in under 5 hours.

[SudiptaPaul-31]

May I be assigned to this issue please my name is Sudipta Paul a active open source contributor with more than 50+ merged pr's and also an active contributor of GrantFox from begining and would love to work on this issue and get a pr merged

[grantfox-oss]

🦊 GrantFox — @mijinummi has been assigned to this issue as part of the Official Campaign campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #2)
2. Your PR will be reviewed by the Exquisitech maintainers

Good luck! Track your progress on GrantFox.