Header doesn't match policyengine-app-v2 and lacks www redirect

[anth-volk]

Problem

The header bar in the API docs doesn't match the header in policyengine-app-v2. It uses a solid background instead of the gradient, wrong border color, simplified font stack, and lacks the Apple-style animated dropdowns.

Additionally, there are no redirects for www-to-non-www domain access.

Expected

• Header should be an exact visual match to the policyengine-app-v2 header
• www.policyengine.org should redirect to policyengine.org