[web] Share third-party integration icons + add Papers icon (#33537)

* [web] Add Papers/ReadCube icon to plans page integrations

Closes #33493

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* Delete old 200kB zotero logo

* Allow png use in logos

* Allow wrap

* [web] Share third-party integration icon list across plans and onboarding pages

Extract the icons array to services/web/app/src/util/third-party-icons.mjs
so the plans-2026 feature table and the try_premium onboarding page render
from a single source. The try_premium page now also includes Papers and
follows the plans page ordering.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* [web] Allow ciam try-premium logo row to wrap

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
GitOrigin-RevId: f5a52418cbe01d9e343092b552183dffa3ae78bd

services/web/frontend/stylesheets/ciam/ciam-try-premium.scss

@@ -1,5 +1,6 @@
 .ciam-try-premium-logo-container {
   display: flex;
+  flex-wrap: wrap;
   justify-content: center;
   gap: var(--ds-spacing-600);
   padding: var(--ds-spacing-200) 0 var(--ds-spacing-500) 0;

services/web/frontend/stylesheets/pages/plans-2026.scss

@@ -688,6 +688,7 @@
   .plans-feature-table-section-icons {
     align-items: center;
     display: flex;
+    flex-wrap: wrap;
     gap: var(--spacing-04);
   }