page with verification

[Truphile]

closes
#20

Summary of Changes:

1. Created VERIFICATION.md: Documented the SHA-256 hashes for all 5 core
   StepFi smart contracts (Creditline, Reputation, Liquidity Pool, Vendor
   Registry, and Parameters) and provided a step-by-step guide for developers
   to verify the on-chain bytecode against the source code.
2. Implemented src/pages/Contracts.tsx: Created a new page that displays:
   • Contract names and descriptions.
   • Direct links to the contracts on Stellar Expert (Testnet).
   • Copyable Contract IDs.
   • SHA-256 hashes for manual verification.
   • An embedded Self-Verification Guide with shell commands for cloning,
     building, and hashing the contracts.
3. Router and UI Updates:
   This task focused on enhancing the protocol's transparency and security by
   allowing users to independently verify the integrity of the deployed smart
   contracts.