fix(ci): Correct repo path format for plugins/docker

The repo setting should NOT include the registry prefix - the
registry setting handles that separately.

Changed repo: reg.mosaicstack.dev/mosaic/api -> repo: mosaic/api

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.woodpecker.yml

@@ -88,7 +88,7 @@ steps:
     image: plugins/docker
     settings:
       registry: reg.mosaicstack.dev
-      repo: reg.mosaicstack.dev/mosaic/api
+      repo: mosaic/api
       dockerfile: apps/api/Dockerfile
       context: .
       tags:
@@ -108,7 +108,7 @@ steps:
     image: plugins/docker
     settings:
       registry: reg.mosaicstack.dev
-      repo: reg.mosaicstack.dev/mosaic/web
+      repo: mosaic/web
       dockerfile: apps/web/Dockerfile
       context: .
       build_args:
@@ -130,7 +130,7 @@ steps:
     image: plugins/docker
     settings:
       registry: reg.mosaicstack.dev
-      repo: reg.mosaicstack.dev/mosaic/postgres
+      repo: mosaic/postgres
       dockerfile: docker/postgres/Dockerfile
       context: docker/postgres
       tags: