deploy: Deploy the registry to GCP

[domdomegg]

Adds the Pulumi code to:

• Deploy the registry (and associated services e.g. mongodb) to Google Cloud Platform (GCP), on top of Google Kubernetes Engine (GKE)
• Sets up proper environments and secrets management
• Uses the real container image, now that it's published in Add Docker image documentation and workflow #225. At the moment attached to latest, we might want to pin the version later (or perhaps always use latest in staging, and pin prod)
• Uses real domains (staging.registry.modelcontextprotocol.io) rather than examples (``)

Motivation and Context

Setting up infrastructure to deploy it. I set something up in Azure in #227, although not super robust (e.g. no service accounts etc.). Think we will use GCP as:

• the maintainers have experience with GCP, but none with Azure
• costs are quite low, and Anthropic is happy to cover them in the short term
• means we only have to maintain one login system (just Google Cloud Identity), not two (Google Workspace + Azure)

How Has This Been Tested?

Deployed this to a staging and production cluster. Try it yourself at:

curl -H "Host: staging.registry.modelcontextprotocol.io" -k https://35.222.36.75/v0/ping

(will be sorting out domains very soon)

Breaking Changes

NA - just adds support for GCP deployment

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation update

Checklist

• I have read the MCP Documentation
• My code follows the repository's style guidelines
• New and existing tests pass locally
• I have added appropriate error handling
• I have added or updated documentation as needed

Additional context

Expected follow-ups:

• GitHub Action setup to deploy things to the cluster from GitHub, to avoid gatekeeping to just the people with the secrets.