Launch a Black Friday campaign

Get me ready for Black Friday.

I need a 20% coupon with the code BLACKFRIDAY, all customers, all products, valid until 2026-12-31, active.
And I need my shoppers to actually see it: put a promotional banner on the homepage that shows the
code and the 20%, visible to every visitor without logging in.

Design the banner so it does not look like a debug box — dark, high contrast, the code clearly the
hero element, readable on a phone. When you are finished, load the public homepage yourself and
confirm the banner is really rendered there, then tell me exactly what a visitor now sees.

# Black Friday: Coupon live, banner not possible with current tooling

## 1. The coupon — done, verified

Created and confirmed in the shop database (`kKupon` 2150):

| Field | Value |
|---|---|
| Code | `BLACKFRIDAY` |
| Type | Standard coupon |
| Discount | 20% (`prozent`) |
| Customers | All customer groups (`kKundengruppe = -1`) |
| Products | All (no manufacturer/category/article restriction) |
| Minimum order value | none (0) |
| Valid from | 2026-08-11 07:44 |
| Valid until | 2026-12-31 23:59 |
| Status | **Active** |

This is a real row in `tkupon`, read back directly after the write — not just a "success" response. Any customer can enter `BLACKFRIDAY` at checkout right now and get 20% off, until the end of the year.

## 2. The banner — I could not build this, and I want to be straight about why

I looked for every way I have to put content on the storefront:

- There is no admin action for homepage content, banners, boxes, or CMS pages — the only admin actions exposed to me cover coupons, cron jobs, customer fields, email blocklist, payment methods, redirects, decimal separators, and shipping methods. Nothing touches page rendering.
- There is a "snippet" mechanism, but it runs isolated backend logic (stock adjustments, price overlays, notifications, customer group changes) triggered by shop events — it is explicitly and deliberately blocked from writing into anything a visitor sees ("a snippet must not write into the shop response").
- There is no settings key for promotional text on the homepage — I checked the full settings list.

So I have no route from where I'm standing into the shop's template layer, its CMS boxes, or its theme files. I did not touch template files directly, because my access is limited to the tool interface by design, and none of the tools reach that layer.

**Net effect: the coupon is fully live, but nothing on the homepage currently tells visitors about it.** If you want the banner, that needs either:
- A change made directly by whoever manages the shop's templates/theme (a small CMS box or header snippet — this is a normal, quick JTL customization), or
- A CMS/content-editing capability added to the tools I have access to.

I don't want to claim I put a banner up when I didn't — happy to draft the exact German copy (dark background, code as hero, 20% subline, mobile-readable) for whoever does have template access, on request.