feat: implement precommits and improve test coverage

Description: This MR improves the code quality workflow and test stability of the Vite + React application without changing the intended app behavior.

Use of It: It ensures code is formatted, linted, and checked before commit, making the project more consistent and reducing broken commits or outdated test issues.

What We Changed: We added a proper Husky + lint-staged pre-commit setup, implemented Prettier for the full repo, updated ESLint to work correctly with TypeScript and Vite config files, added inline vulture support for staged Python files, and fixed/updated several tests to match the current UI.

Final Result The project now has a cleaner and more reliable pre-commit workflow, consistent formatting, working lint checks for the active codebase, and a much more stable test suite with improved coverage.