Ship Print Forge shop site (colors, photos, 3D viewer) (#2)

## Summary

- Rebrand the Django client template as Print Forge (`client_site` → `print_forge`) with shop + shipping enabled.
- Product listings support multiple photos, color variants (shared price/description/STL, per-color stock and photos), and a photo-first / 3D-second gallery.
- Public pages use 3D printer / printed-toy photography instead of leftover t-shirt mockups; beta CI deploys on `master`.

Closes #1
Infra: [server-infra#27](ai_ml_operations/server-infra#27) (easy deploy beta).

## Test plan

- [ ] Product page shows photo first, 3D model second; color swatches swap photos and stock
- [ ] Portal can upload multiple photos and per-color qty/images; STL stays shared
- [ ] Public home/about/gallery have no t-shirt mockups
- [ ] `manage.py test` passes
- [ ] After server-infra#27: beta deploy to `print-forge-preview.aimloperations.com`

Reviewed-on: #2

site/accounts/templates/accounts/login.html

@@ -5,7 +5,8 @@
   <meta charset="utf-8">
   <meta name="viewport" content="width=device-width, initial-scale=1">
   <title>Sign in · Portal · {{ SITE_NAME }}</title>
-  <link rel="icon" href="{% static 'brand/favicon-32.png' %}" type="image/png">
+  <link rel="icon" href="{% static 'brand/favicon.ico' %}" type="image/x-icon">
+  <link rel="apple-touch-icon" href="{% static 'brand/apple-touch-icon.png' %}">
   <link rel="stylesheet" href="//fonts.googleapis.com/css?family=Work+Sans:300,400,500,700%7CPoppins:400,600,700">
   <link rel="stylesheet" href="{% static 'css/portal.css' %}">
 </head>