fix navigation links, footer categories, product card structure, and social icons

- add missing cta_href to hero section and error page CTAs
- replace hardcoded footer shop links with real product categories
- restructure product cards with stretched-link pattern so category
  badges link to their collection page
- unify social icons: footer and contact page share the same default
  links from a single source in content.ex
- add search implementation plan (docs/plans/search.md, deferred)

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

PROGRESS.md

@@ -53,11 +53,10 @@ Issues found during hands-on testing of the deployed prod site on mobile and des
 - [ ] Shipping costs: add Stripe shipping options or query Printify for dynamic rates
 
 ### Navigation & links
-- [ ] Search doesn't work (modal opens but no results/functionality)
-- [ ] "Shop the collection" button/link does nothing
-- [ ] Footer "New arrivals" and "Best sellers" links don't go anywhere
-- [ ] Should be able to tap a category badge on product cards to go to that category
-- [ ] Footer social icons should match the "Find me on" icons from the contact page
+- [x] "Shop the collection" button/link does nothing
+- [x] Footer "New arrivals" and "Best sellers" links don't go anywhere
+- [x] Should be able to tap a category badge on product cards to go to that category
+- [x] Footer social icons should match the "Find me on" icons from the contact page
 
 ### Collections / all products
 - [ ] Categories on all-products page are too spaced out
@@ -71,6 +70,9 @@ Issues found during hands-on testing of the deployed prod site on mobile and des
 ### Errors
 - [ ] 404 page is broken
 
+### Search (deferred — after usability fixes)
+- [ ] Search doesn't work (modal opens but no results/functionality) — see [docs/plans/search.md](docs/plans/search.md)
+
 ## Roadmap
 
 ### Tier 1 — MVP (can take real orders and fulfil them)