Add authorization rejection tests for harvest_yield and emergency_pause

[Code-Paragon]

Problem

While harvest_yield and emergency_pause use require_auth(), the test suite never explicitly verifies that an unauthorized actor calling these functions is successfully rejected by the environment.

Expected behavior

The test suite utilizes the env.mock_auths or expected panic attributes to simulate a random user calling admin/keeper functions, verifying the transaction reverts.

Files to update

• src/test.rs

Project relevance

Cryptographically guarantees the Vault's access control modifiers are functioning correctly, preventing malicious LPs from pausing the contract or spoofing yields.

Acceptance criteria

• Feature works as described
• Tests are added or updated where needed
• Documentation is updated where needed
• Test asserts failure when a non-admin Address attempts to invoke emergency_pause
• No TypeScript, lint, test, or build errors