[Testing] MultisigGovernance cross-contract set_admin is only tested against a MockTarget, never a real RemitLend contract

[grantfox-oss]

Telegram (ask questions / claim the issue here first): https://t.me/+DOylgFv1jyJlNzM0

Why this matters

contracts/multisig_governance/src/test.rs:41 registers a local MockTarget and asserts MockTargetClient.get_admin(), so the finalize_admin_transfer -> set_admin invocation is never exercised against the actual LendingPool/RemittanceNFT (which expose set_admin) or LoanManager (which does not). The crate has no path dev-dependency on the real contracts, so the symbol/arg-type/auth mismatch that breaks the real deployment is invisible to the suite.

Acceptance criteria

• Add lending_pool/remittance_nft as path dev-dependencies of multisig_governance (matching loan_manager's test wiring)
• Add an integration test that registers a real RemitLend contract, runs propose -> approve -> finalize, and asserts the real contract's admin actually changed
• Add a negative test asserting finalize against a target lacking set_admin fails clearly

Files to touch

• contracts/multisig_governance/src/test.rs
• contracts/multisig_governance/Cargo.toml

Out of scope

• Cross-contract fuzzing
• Frontend governance console tests