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/manage.py

@@ -7,7 +7,7 @@ import sys
 
 def main() -> None:
     """Run administrative tasks."""
-    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "client_site.settings")
+    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "print_forge.settings")
     try:
         from django.core.management import execute_from_command_line
     except ImportError as exc: