SEO audit findings resolved across app, feedback, and marketing

A batch of SEO audit findings landed in one pass across all three surfaces:

• Admin app: root redirect upgraded from 302 to 301, meta descriptions extended past the audit-tool threshold, dead-end fixes on the password-reset flow.
• Feedback portal: missing canonical links restored, sitemap re-emitting all public boards, OG metadata properly declared per post.
• Marketing: title-tag length tuned, structured data restructured into the @graph form, brotli compression enabled on small responses.

The audit dashboard moved from yellow to green on every surface.