fix: restore Apache footer logos and refine homepage

[dengliming]

Summary

Restore the two Apache images omitted from the shared footer in #1148, using the original, unchanged assets. Add a white background behind the ASF logo for contrast and center the copyright and trademark notices.

 Shared footer
+  Support Apache + ASF logos
-  Left-aligned legal notices
+  Centered legal notices
 Homepage
-  Technology ecosystem strip
-  Request flow selected first
+  Architecture selected first; request flow second

Remove the unused ecosystem styles and English/Chinese copy. Keep both diagram cards and their switching controls.

Evidence

• Before: rendering the original shared footer failed the image check with Missing footer image: support-apache.png.
  After: rendering the updated component passes for both image references and existing assets. Both files are byte-identical to the assets before feat: refresh website design and community pages #1148.
• English and Chinese development builds compiled successfully. Browser checks confirmed the architecture card is selected first, both cards still switch, and the ecosystem strip is absent.
• Verified both footer images load on desktop and at 320px, with no horizontal overflow and a visible keyboard focus outline. Confirmed both legal paragraphs compute to text-align: center on the users page.
• Changed CSS and translation JSON parse successfully; git diff --check passes.

Merge Danger

Door: Two-way. Reversible UI-only changes.

Blast Radius: Presentation. The shared footer changes apply to all pages in both locales; the remaining changes affect the homepage.