Implement Soroban Auth Framework

This issue tracks the implementation of the Soroban Authorization Framework within the Soroban semantics. Specifically, we aim to properly implement the two host functions that are currently no-ops:

• require_auth
• authorize_as_curr_contract

Implementing these is essential for enabling accurate reasoning about the authorization properties of Soroban smart contracts using Komet.

Currently, require_auth and authorize_as_curr_contract are stubbed and do not affect contract execution or analysis. As a result, Komet cannot model or analyze the authorization behavior of Soroban contracts. Once these functions are correctly implemented, Komet will be able to check authorization flows.

TODO:

• require_auth
• authorize_as_curr_contract

Resources:

• Soroban Auth Docs: https://developers.stellar.org/docs/learn/encyclopedia/security/authorization

Priority: High

Start with the Soroban Auth Docs linked in the issue, then locate the Komet semantics implementations of the stubbed require_auth and authorize_as_curr_contract host functions. Done means both functions affect contract execution or analysis so Komet can check authorization flows.