feat: add heroku-mcp-server MCP server package

Add packaging for heroku-mcp-server v1.0.7.
This server enables seamless interaction between LLMs and the Heroku Platform,
providing tools for managing apps, dynos, add-ons, pipelines, databases, and more.

Key features:
- Application management (create, rename, transfer, deploy)
- Process & dyno management (scale, restart, list)
- Add-on provisioning and management
- Pipeline operations (create, promote, info)
- PostgreSQL database management (queries, backups, maintenance)
- Maintenance mode control
- Log viewing
- Team & space management

Package: https://www.npmjs.com/package/@heroku/mcp-server
Repository: https://github.com/heroku/heroku-mcp-server

Author: JAORMX

npx/heroku-mcp-server/spec.yaml

@@ -0,0 +1,19 @@
+# Heroku MCP Server Configuration
+# MCP server for interacting with the Heroku Platform
+# Package: https://www.npmjs.com/package/@heroku/mcp-server
+# Repository: https://github.com/heroku/heroku-mcp-server
+# Will build as: ghcr.io/stacklok/dockyard/npx/heroku-mcp-server:1.0.7
+
+metadata:
+  name: heroku-mcp-server
+  description: "MCP server for seamless interaction between LLMs and the Heroku Platform"
+  version: "1.0.7"
+  protocol: npx
+
+spec:
+  package: "@heroku/mcp-server"
+  version: "1.0.7"
+
+provenance:
+  repository_uri: "https://github.com/heroku/heroku-mcp-server"
+  repository_ref: "refs/heads/main"