[Testing] RemittanceNFT pause/unpause gating has zero coverage

[grantfox-oss]

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

Why this matters

remittance_nft/src/lib.rs:367-378 assert_not_paused is invoked by require_admin_or_authorized_minter, approve_remint, admin_remint, and set_default_burn_threshold, but remittance_nft/src/test.rs contains no test that calls pause()/unpause(). The ContractPaused (error 13) branch and the unpause-restores-operation path are completely unexercised.

Acceptance criteria

• Test that after pause(), mint/update_score/admin_remint/approve_remint fail with NftError::ContractPaused
• Test that unpause() restores normal operation
• Test is_paused() reflects state transitions and that Paused/Unpaused events are emitted

Files to touch

• contracts/remittance_nft/src/test.rs

Out of scope

• Adding new pause semantics to the contract