feat(field-guide): out of hiding — homepage showcase, hub OG, and "A field guide to your own machine"

Makes the Field Guide a visible permanent tenant of the Vera ecosystem, and
ships a long-form announcement to go with it.

The blog post (data/posts/the-field-guide.md, "A field guide to your own
machine") is roughly an eight-minute read written for the young, smart,
skeptical gamer. Opens with the plain truth that millions of people have
RTCore64.sys on their machine because they installed MSI Afterburner. …