Add JSDoc comments to RabbitMQBroker public methods

[sohaibqasem]

Add JSDoc comments to RabbitMQBroker public methods

Some public methods in RabbitMQBroker could benefit from clearer JSDoc comments to improve IDE hints and developer understanding.

This issue is about adding descriptive JSDoc comments only, without changing behavior.

Scope

• Update RabbitMQBroker public methods
• No logic or behavior changes
• Keep comments concise and clear

Acceptance Criteria

• Public methods are documented
• No functional changes
• TypeScript tooling shows improved hints

Notes for Contributors

This is a safe, low-risk task and a good introduction to the codebase.