feat: enhance SEO capabilities and add All Tools page

- Updated generate-seo-assets script to create separate sitemap files for static, blog, tools, and SEO pages.
- Introduced render-seo-shells script to generate HTML shells for SEO pages with dynamic metadata.
- Added All Tools page with categorized tool listings and SEO metadata.
- Updated routing to include /tools path and linked it in the footer.
- Enhanced SEOHead component to remove unused keywords and improve OpenGraph metadata.
- Updated translations for tools hub in English, Arabic, and French.
- Refactored SEO-related utility functions to support new structured data formats.

frontend/src/i18n/en.json

@@ -256,6 +256,19 @@
       "contactTitle": "8. Contact",
       "contactText": "Questions about these terms? Contact us at"
     },
+    "toolsHub": {
+      "metaTitle": "All Tools",
+      "metaDescription": "Browse every Dociva tool in one place. Explore PDF, image, AI, conversion, and utility workflows from a single search-friendly directory.",
+      "title": "All Dociva Tools",
+      "description": "Use this directory to explore every Dociva workflow by category and jump directly to the tool you need.",
+      "categories": {
+        "PDF": "PDF Tools",
+        "Convert": "Convert Tools",
+        "Image": "Image Tools",
+        "AI": "AI Tools",
+        "Utility": "Utility Tools"
+      }
+    },
     "cookie": {
       "title": "Cookie Settings",
       "message": "We use cookies to improve your experience and analyze site traffic. By accepting, you consent to analytics cookies.",