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

scripts/validate-env.sh

@@ -82,6 +82,41 @@ if _true "${FEATURE_SOCIAL_AI:-}"; then
     exit 1
   fi
 fi
+if _true "${FEATURE_SHOP:-}"; then
+  if ! _true "${FEATURE_EMAIL_SMS:-}"; then
+    echo "FEATURE_SHOP requires FEATURE_EMAIL_SMS" >&2
+    exit 1
+  fi
+  if ! _true "${FEATURE_PAYMENTS:-}"; then
+    echo "FEATURE_SHOP requires FEATURE_PAYMENTS" >&2
+    exit 1
+  fi
+fi
+if _true "${FEATURE_POS_SYNC:-}"; then
+  if ! _true "${FEATURE_SHOP:-}"; then
+    echo "FEATURE_POS_SYNC requires FEATURE_SHOP" >&2
+    exit 1
+  fi
+  if [[ "$DJANGO_ENV" == "prod" || "$DJANGO_ENV" == "beta" ]]; then
+    required_vars+=(POS_WEBHOOK_SECRET)
+  fi
+fi
+if _true "${FEATURE_EVENTS:-}"; then
+  if ! _true "${FEATURE_EMAIL_SMS:-}"; then
+    echo "FEATURE_EVENTS requires FEATURE_EMAIL_SMS" >&2
+    exit 1
+  fi
+  if ! _true "${FEATURE_PAYMENTS:-}"; then
+    echo "FEATURE_EVENTS requires FEATURE_PAYMENTS" >&2
+    exit 1
+  fi
+fi
+if _true "${FEATURE_SHIPPING:-}"; then
+  if ! _true "${FEATURE_SHOP:-}"; then
+    echo "FEATURE_SHIPPING requires FEATURE_SHOP" >&2
+    exit 1
+  fi
+fi
 
 missing=()
 for var in "${required_vars[@]}"; do
@@ -93,7 +128,7 @@ done
 if ((${#missing[@]} > 0)); then
   echo "Missing required environment variables in $ENV_FILE:" >&2
   printf '  - %s\n' "${missing[@]}" >&2
-  echo "Copy .env.prod.example to ~/Documents/secrets/<slug>_site/<slug>_site_${DJANGO_ENV}.env and set values." >&2
+  echo "Copy .env.prod.example to ~/Documents/secrets/print_forge/print_forge_${DJANGO_ENV}.env and set values." >&2
   exit 1
 fi