Per design feedback, restructure the mobile product page (desktop layout
unchanged except color swatches):
- remove the top seller bar; the seller/brand (logo + name + ارسال پیام)
now sits in a row below the gallery.
- add a floating circular back button over the image (safe-area aware).
- move the rating out of the action row into a prominent body row, shown
only when the average rating is > 0.
- color swatches are now circles with a selection ring (shared with
desktop for consistency) instead of squares.
- make the افزودن به سبد خرید button full-width/taller with a compact
price beside it.
- the action row keeps save / share / add-to-collection / try-on.
- the red discount icon is kept as-is.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>