Improve Replicated release promotion workflow

[marccampbell]

Summary

• automatically bump the Replicated/Helm patch version before creating a release
• keep Chart.yaml and the KOTS HelmChart chartVersion synchronized while leaving container appVersion unchanged
• add guarded Beta and Stable targets that promote an existing release sequence
• reliably restore temporary local proxy substitutions on failure
• document the release and promotion commands

Verification

• exercised bump target in an isolated fixture: 0.3.1 -> 0.3.2
• verified Chart.yaml and replicated/helmchart.yaml synchronize to 0.3.2
• verified Chart.yaml appVersion remains 0.0.162
• verified missing sequence and unsupported channel guards
• git diff --check