chore: remove unused images, update project image paths to webp format, and enhance accessibility with aria-labels across components

package.json

@@ -70,7 +70,6 @@
     "react-icons": "^5.5.0",
     "rehype-document": "^7.0.3",
     "rehype-external-links": "^3.0.0",
-    "rehype-katex": "^7.0.1",
     "rehype-pretty-code": "^0.14.1",
     "remark-emoji": "^5.0.1",
     "remark-math": "^6.0.0",