ROX-31487: Add helm chart

[mtodor]

Description

This PR is adding helm chart from StackRox MCP server

Additional changes:

• additional style checks are added for helm template
• Dockerfile is modified to better support Openshift security context constraints (SCCs)

TODO

• add Makefile targets for helm lint
• add helm command example to project README

Validation

• usual helm lint (part of CI)
• deploy on Openshift cluster and test
• test new Dockerfile
• deploy on GKE cluster and test

An example command to deploy helm:

helm upgrade --install stackrox-mcp charts/stackrox-mcp \
  --namespace stackrox-mcp-helm \
  --create-namespace \
  --set config.tools.vulnerability.enabled=true \
  --set config.central.url=<Central URL>:443 \
  --set image.tag=<Image Tag> \
  --set config.central.insecureSkipTLSVerify=true

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 77.36%. Comparing base (53e4b0b) to head (41440c8).
✅ All tests successful. No failed tests found.

Additional details and impacted files

@@           Coverage Diff           @@
##             main      #23   +/-   ##
=======================================
  Coverage   77.36%   77.36%           
=======================================
  Files          26       26           
  Lines        1109     1109           
=======================================
  Hits          858      858           
  Misses        216      216           
  Partials       35       35           

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[janisz]

I'm not sure if this should be exposed in helm. Static is fine for testing but for real deployment I think we should promote m2m Auth if mcp needs to be authenticated. On the other hand I could imagine it could be useful but its should be noted what are the consequences.

[janisz]

Maybe it should be true so an example is working out of the box