feat: surface required authorizations for the simulated call

[Hollujay]

Summary

Simulation precomputes the SorobanAuthorizedInvocation trees that must be
authorized for require_auth checks to pass. That answers "what am I actually
signing?" — directly relevant to this tool's purpose of showing consequences
before submission.

Acceptance Criteria

• Extract the auth entries from the simulation response
• Render which addresses must authorize, and for which sub-invocations
• Show nested/cross-contract invocation structure, not just a flat list
• Say plainly when a call requires no authorization

Tech Stack

TypeScript, @stellar/stellar-sdk