Match banner brand, print splash, optional crop, and demo seed (#6)

## Summary
- Rebrand public site, portal, and emails from Ecoprint orange to the PRINTFORGE banner palette (navy / cyan / lime).
- Replace the loading splash with a CSS 3D-print animation; product uploads get a default-on smart crop + background filter checkbox.
- Add `manage.py seed_demo` for client walkthroughs on dev/beta only (refuses prod).

Closes #5.

## Test plan
- [ ] Public pages and buttons are cyan/lime, not orange
- [ ] Splash shows a printer building a model (or a static print if reduced motion)
- [ ] Product edit: smart-crop checked by default; uncheck stores the original photo
- [ ] `uv run python manage.py seed_demo` fills shop, contacts, leads, orders, campaigns
- [ ] `DJANGO_ENV=prod` seed_demo exits with an error

Reviewed-on: #6

site/shop/services.py

@@ -418,7 +418,7 @@ def normalize_hex(value: str) -> str:
     return raw.lower()
 
 
-def store_product_image(*, upload, user) -> StoredFile:
+def store_product_image(*, upload, user, smart_crop: bool = True) -> StoredFile:
     content_type = (getattr(upload, "content_type", None) or "").lower()
     if content_type not in _ALLOWED_IMAGE_TYPES:
         raise ShopError("Use a JPEG, PNG, GIF, or WebP image.")
@@ -427,15 +427,18 @@ def store_product_image(*, upload, user) -> StoredFile:
         raise ShopError("Image must be 15 MB or smaller.")
     original = (getattr(upload, "name", None) or "product")[:255]
     try:
-        from shop.imaging import prepare_product_photo, product_image_filename
+        from shop.imaging import open_image, prepare_product_photo, product_image_filename
     except ImportError as exc:
         logger.exception("product photo processing dependencies missing")
         raise ShopError(
             "Image processing is not installed. Rebuild the app container."
         ) from exc
     try:
-        data, content_type = prepare_product_photo(data)
-        original = product_image_filename(original)
+        if smart_crop:
+            data, content_type = prepare_product_photo(data)
+            original = product_image_filename(original)
+        else:
+            open_image(data)
     except ShopError:
         raise
     except Exception as exc:
@@ -569,12 +572,15 @@ def append_product_images(
     uploads,
     user,
     color: ProductColor | None = None,
+    smart_crop: bool = True,
 ) -> None:
     existing = product.images.filter(color=color).count()
     for offset, upload in enumerate(uploads):
         if not upload:
             continue
-        stored = store_product_image(upload=upload, user=user)
+        stored = store_product_image(
+            upload=upload, user=user, smart_crop=smart_crop
+        )
         ProductImage.objects.create(
             product=product,
             color=color,