feat(eks-mcp-server): add hosted MCP server documentation and registry metadata

[djtung]

Summary

Changes

• Add server.json metadata file used for publishing EKS hosted MCP to the Official MCP Registry
• Update README to announce new hosted MCP server offering from EKS
• Fix package name build script to allow for optional dependency names. We use the mcp-proxy-for-aws in the hosted setup which is called out in the README

User experience

Users can now setup the EKS MCP server with a hosted option, eliminating local infra

Checklist

If your change doesn't seem to apply, please leave them unchecked.

• I have reviewed the contributing guidelines
• I have performed a self-review of this change
• Changes have been tested
• Changes are documented

Is this a breaking change? N

RFC issue number:

Checklist:

• Migration process documented
• Implement warnings (if it can live side by side)

Acknowledgment

By submitting this pull request, I confirm that you can use, modify, copy, and redistribute this contribution, under the terms of the project license.

[codecov]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 90.45%. Comparing base (2c368b7) to head (a19f979).

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1870      +/-   ##
==========================================
- Coverage   90.46%   90.45%   -0.01%     
==========================================
  Files         854      854              
  Lines       63831    63831              
  Branches    10372    10372              
==========================================
- Hits        57742    57740       -2     
  Misses       3785     3785              
- Partials     2304     2306       +2     

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[srhsrhsrhsrh]

LGTM

[patrick-yu-amzn]

LGTM

[srhsrhsrhsrh]

Some details for reviewers:

1. Verified that the verify package script fails without the modifications

❌ Package name verification failed for awslabs.eks-mcp-server
  - Package name mismatch: found 'mcp-proxy-for-aws' but expected 'awslabs.eks-mcp-server' (line 51)

2. io.github.awslabs/eks-mcp-server as the name in server.json resolves to this repo - see https://github.com/modelcontextprotocol/registry/blob/d840378a3a495bc55b70f6c7146686e854249538/docs/reference/server-json/official-registry-requirements.md#registry-api-metadata-vs-serverjson-metadata. It's not a link - it serves as an identifier based on the conventions in the MCP registry.

3. The local server references are left in README.md since it hasn't been deprecated yet.