[Feature] Contract Upgradability Pattern (WASM Swap)

[AlAfiz]

Description: We need a secure, admin-controlled mechanism to upgrade the smart contracts without migrating liquidity or losing state.
Context / Motivation: TradeFlow is in active development. We must be able to patch bugs and deploy new features to the core contracts without disrupting user balances or breaking frontend integrations.
Acceptance Criteria: - [ ] Implement an upgrade function in the core contracts.

• Ensure the function requires authorization strictly from the designated Admin address.
• Utilize env.deployer().update_current_contract_wasm() to swap the executable code.
• Write integration tests verifying state persists across a mock upgrade.
  Technical Pointers: Review the Soroban documentation on contract upgrades. Pay close attention to how data schemas in storage are handled post-upgrade; ensure no breaking changes in storage struct definitions occur in your tests.

[gloskull]

Hi, I would love to work on this Issue.
I have 4 years of experience delivering solutions for projects like this, covering backend, frontend, full-stack and smart contract development. After carefully reviewing your requirements, I have a clear understanding of the task and am confident in my ability to deliver a clean, efficient, and thoroughly tested solution on time. I prioritize code quality, maintainability, and industry best practices throughout the development process.
My PR will be submitted in under 10hours.

[damzempire]

i would like to work on this issue as a full stack developer

[ghost-cy829]

I would like to work on this issue. I have experience with Rust and Soroban smart contract development. I will follow the acceptance criteria and add tests. Excited to contribute. Kindly assign.