Remove all Paris branding references

Journal is online-only; removed "gathered in Paris" from footer and
imprint, "· Paris" from logo tagline and 404 colophon, and the Paris
span from the header nav. Post content (paris-bridge-crimson-dusk)
left untouched as that refers to the photograph subject.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

layouts/partials/header.html

@@ -28,8 +28,6 @@
       <a href="/issues/" class="nav-link">Issues</a>
       <span class="opacity-50 max-[820px]:hidden">·</span>
       <a href="/imprint/" class="nav-link whitespace-nowrap max-[820px]:hidden">Imprint</a>
-      <span class="opacity-50 max-[1100px]:hidden">·</span>
-      <span class="whitespace-nowrap max-[1100px]:hidden">Paris</span>
     </div>
   </div>