**Add continuous reading mode and enhance accessibility in TheComicReader**

- Introduced a continuous reading mode ("scroll"), allowing users to read without pagination.
- Implemented a toggle in the UI to switch between "paged" and "continuous" modes, with preferences saved in `localStorage`.
- Enhanced keyboard navigation by throttling repeated actions and ignoring irrelevant keypresses during form interactions.
- Integrated `IntersectionObserver` to handle lazy-loading of images and dynamically extending rendered content in continuous mode.
- Updated tests to validate both reading modes, ensuring proper state management and observer handling.
- Adjusted animations and transitions for smoother visual feedback in both modes, respecting users' motion-reduction preferences.

frontend/eslint.config.mjs

@@ -52,6 +52,7 @@ export default [
         console: 'readonly',
         setTimeout: 'readonly',
         clearTimeout: 'readonly',
+        IntersectionObserver: 'readonly',
         process: 'readonly',
       },
     },