feat: publish core chart before remaining charts

[LukaszEV]

Summary

• Split the single release job into two sequential jobs: release-core → release-remaining
• Job 1 removes all charts except core and publishes it first
• Job 2 waits for the new core version to be available in the Helm repo index, then publishes remaining charts
• This prevents dependency resolution failures when core and dependent charts are updated in the same merge

Changes

• .github/workflows/publish.yaml — two-job workflow with needs dependency and wait loop for GitHub Pages cache

Test plan

• Workflow YAML syntax validated
• Pipeline tested on test/pipeline-ordering branch — both jobs run sequentially
• Wait step correctly resolves needed core version from dependent charts