feat: extract shop from mp/shop — initial libreshop/shop

Source moved verbatim from mp/shop/ on 2026-04-29; mp was the first
concrete adapter consuming the libreshop toolkit. Builds and publishes
git.librete.ch/libreshop/shop on every main / v* push via the standard
.gitea/workflows/build.yml shared across libreshop components.

README.md

@@ -0,0 +1,25 @@
+# libreshop/shop
+
+Vue/Nuxt-style storefront base.
+
+Part of the [libreshop](https://git.librete.ch/libreshop) toolkit. Image
+published at `git.librete.ch/libreshop/shop` on every push to `main`
+and on `v*` tags.
+
+## Source
+
+This repo was extracted from `mp/shop/` on 2026-04-29; mp was the
+first concrete adapter consuming the toolkit. mp's `compose.yml` now
+pulls `git.librete.ch/libreshop/shop:<pin>` instead of building locally.
+
+## Build locally
+
+```
+docker build -t libreshop/shop:dev .
+```
+
+## Adapter contract
+
+See `docker-entrypoint.sh` and `Dockerfile` for the runtime surface.
+Adapters configure the component via env vars and bind-mounted volumes;
+do not patch the running container or rely on internal paths.