fix: don't use registryBaseUrl in server.json (#325)

* fix: don't use registryBaseUrl in server.json

[These docs][docs] are misleading, apparently oci images shouldn't
use registryBaseUrl but should just have the full Docker image tag
in the identifier.

[docs]: https://github.com/modelcontextprotocol/registry/blob/main/docs/guides/publishing/publish-server.md#example-serverjson-docker-hub

* add docker.io prefix to MCP registry image identifier

---------

Co-authored-by: Ioanna Armouti <[email protected]>

Author: sd2k

.github/workflows/docker.yml

@@ -73,11 +73,8 @@ jobs:
         run: |
           # Update the server.json with the correct Docker image reference
           # (note the image tag does not include the "v" prefix)
-          jq --arg version "${{ steps.version.outputs.VERSION }}" \
-             --arg image "grafana/mcp-grafana:${{ steps.image-tag.outputs.IMAGE_TAG }}" \
-             '.packages[0].version = $version |
-              .packages[0].identifier = $image |
-              .version = $version' server.json > server.json.tmp
+          jq --arg image "docker.io/grafana/mcp-grafana:${{ steps.image-tag.outputs.IMAGE_TAG }}" \
+             '.packages[0].identifier = $image' server.json > server.json.tmp
           mv server.json.tmp server.json
 
       - name: Login to MCP Registry

server.json

@@ -10,8 +10,7 @@
   "packages": [
     {
       "registryType": "oci",
-      "registryBaseUrl": "https://docker.io",
-      "identifier": "grafana/mcp-grafana",
+      "identifier": "docker.io/grafana/mcp-grafana",
       "version": "$VERSION",
       "transport": {
         "type": "stdio"