Browser Extension Revamp and Optimization

I have a browser extension (Chrome/Firefox) designed to assist users with workflow optimization. The current codebase has some bugs and requires updates to improve performance and usability. I need a skilled developer to:

1. **Fix Technical Issues:**
- Debug and resolve crashes, errors, or unexpected behavior.
- Optimize code for stability and speed.
- Ensure compatibility with the latest browser versions.

2. **Enhance Features (Non-Automation):**
- Improve the user interface (UI/UX) for better navigation.
- Add productivity-focused tools (e.g., time-tracking integration, customizable shortcuts).
- Expand settings for user preferences (e.g., themes, notifications).

**Skills Required:**
- Expertise in browser extension development (JavaScript, HTML, CSS).
- Experience debugging with Chrome/Firefox DevTools.
- Familiarity with version control (Git/GitHub).
- Ability to write clean, well-documented code.

**Preferred Qualifications:**
- Prior work on browser extensions (portfolio examples welcome).
- Knowledge of WebExtensions API.

**Deliverables:**
- Stable, bug-free extension code.
- Documentation for updates.
- Testing reports for quality assurance.