Add comprehensive unit tests for emergency_pause

[Code-Paragon]

Problem

The emergency_pause circuit breaker is implemented in vault.rs, but test.rs contains no assertions verifying that it successfully blocks deposits and withdrawals when active.

Expected behavior

The test suite is expanded to simulate the admin pausing the vault, followed by assertions that user calls to deposit and withdraw trigger the expected panic.

Files to update

• src/test.rs

Project relevance

This mathematically guarantees the reliability of the protocol's primary security mechanism, ensuring funds can be safely frozen during an external exploit.

Acceptance criteria

• Feature works as described
• Tests are added or updated where needed
• Documentation is updated where needed
• Uses #[should_panic(expected = "Vault is currently paused")] for testing blocked actions
• No TypeScript, lint, test, or build errors