docs: release develop to main

Created by: ihsraham

Summary

• Promotes the current develop branch into main.
• Carries the Sevalla static-site 404 behavior to production: unmatched routes resolve to /404.html with a 404 status through the final _redirects rule.
• Carries redirect validation that checks the catch-all 404 rule, its target, and its final-rule placement.

Validation

• git diff --check upstream/main..upstream/develop