[Chrome Extension] Security and Reliability Improvements #53

Description:
This is a major task to improve the overall quality of the Lytics Chrome Extension. It involves two primary objectives: (1) a comprehensive refactoring to enhance security and reliability, and (2) the resolution of all known outstanding bugs. The refactoring will focus on implementing a stricter permissions model, creating a robust error handling system, and improving UI feedback. The bug-fixing component will aim to create a stable baseline for future development.

Acceptance Criteria (Definition of Done):

The new, stricter permission model is implemented and active.

A structured error handling system is in place for all network requests.

UI loading states are consistently displayed during asynchronous operations.

The onboarding and settings pages are fully functional.

All bugs added as sub-tasks to this ticket are resolved, verified, and closed.