- Implemented JavaScript-based price slider for catalog filtering
- Updated catalog views to handle min/max price inputs and compute slider bounds
- Enhanced templates (`index.html`, `side-bar.html`) with filtering form and updated URLs
- Added CSS for price slider styling and form layout
- Introduced utility functions for URL building and price parsing
- Expanded tests for price filtering, sliders, and sidebar active states
- Updated context processor and header for dynamic navigation with price filters
