Beef up social media link preview

[ecurrencyhodler]

Currently when we drop links into social media platforms, the result is pretty bare. We can level up our marketing for these by adding a basic/standard image, adding a title, and description to these pages.

[cybercraftsolutionsllc]

Submitted frontend implementation PR: stakwork/sphinx-tribes-frontend#1602

What changed:

• Added Open Graph metadata for title, description, image, URL, and site name
• Added Twitter card metadata for title, description, and image
• Updated the default page description to describe Sphinx Community bounties/builders

Validation:

• git diff --check
• Checked public/index.html contains og:title, og:description, og:image, twitter:card, and twitter:image

This is a static metadata-only change to improve link previews without altering app runtime behavior.