ci: use valid chart version for latest releases

[ranxi2001]

What type of PR is this?

/kind bug

What this PR does / why we need it

This PR fixes the release workflow failure on main pushes while keeping latest image publishing enabled.

The release workflow uses TAG=latest for main branch pushes. That value is valid for Docker image tags, but the workflow also reused it as the Helm chart version. Helm chart versions must be valid SemVer values, so helm package --version latest fails with chart.metadata.version "latest" is invalid.

This PR separates Docker image tags from Helm chart metadata:

• On main pushes, Docker images still use TAG=latest, while the Helm chart uses CHART_VERSION=0.0.0 and APP_VERSION=latest.
• On release tag pushes, Docker images, Helm chart version, Helm chart appVersion, the chart package filename, and the Helm OCI tag continue to use the existing Git tag value such as v1.2.3.

Which issue(s) this PR fixes

Fixes #417

Special notes for your reviewer

This intentionally keeps latest image publishing on main pushes and only fixes the invalid Helm chart version used for latest chart publishing.

Validation data:

• main push metadata: TAG=latest, CHART_VERSION=0.0.0, APP_VERSION=latest
• Fork main push validation run: https://github.com/ranxi2001/agentcube/actions/runs/28633043101
• Fork validation result: latest images were published, agentcube-0.0.0.tgz was packaged successfully, and ghcr.io/ranxi2001/charts/agentcube:0.0.0 was pushed successfully.

AI assistance was used to inspect the workflow behavior, validate the fork run result, and prepare this PR text. I reviewed and validated the final change.

Does this PR introduce a user-facing change?

NONE

Additional documentation e.g., usage docs, etc.

None.

What test reports have been run

• git diff upstream/main --check
• actionlint -ignore 'too old to run on GitHub Actions' .github/workflows/build-push-release.yml
• helm lint manifests/charts/base
• Helm package simulation for main push: agentcube-0.0.0.tgz
• Helm package simulation for release tag v1.2.3: agentcube-v1.2.3.tgz
• Helm package simulation for prerelease tag v1.2.3-alpha: agentcube-v1.2.3-alpha.tgz
• Fork main push validation run: https://github.com/ranxi2001/agentcube/actions/runs/28633043101

[gemini-code-assist]

Note

Gemini is unable to generate a review for this pull request due to the file types involved not being currently supported.

[volcano-sh-bot]

[APPROVALNOTIFIER] This PR is NOT APPROVED

This pull-request has been approved by:
Once this PR has been reviewed and has the lgtm label, please assign hzxuzhonghu for approval. For more information see the Kubernetes Code Review Process.

The full list of commands accepted by this bot can be found here.

Details

Needs approval from an approver in each of these files:

• OWNERS

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

[Copilot]

Pull request overview

This PR updates the release publishing GitHub Actions workflow so it only runs on version tag pushes, preventing main branch merges from attempting to publish release artifacts and failing Helm packaging due to non-SemVer chart versions.

Changes:

• Restricts the Build and Push Release Images workflow trigger to tag pushes only (removes main branch push trigger).
• Separates Docker image tagging (TAG=vX.Y.Z...) from Helm chart packaging version (CHART_VERSION=X.Y.Z...) by stripping the leading v.
• Updates Helm chart packaging/push steps to use CHART_VERSION for chart version and .tgz name, while keeping TAG for appVersion and image tags.

[codecov-commenter]

⚠️ Please install the to ensure uploads and comments are reliably processed by Codecov.

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 58.47%. Comparing base (524e55e) to head (427e618).
⚠️ Report is 156 commits behind head on main.
❗ Your organization needs to install the Codecov GitHub app to enable full functionality.

Additional details and impacted files

@@             Coverage Diff             @@
##             main     #416       +/-   ##
===========================================
+ Coverage   47.57%   58.47%   +10.90%     
===========================================
  Files          30       36        +6     
  Lines        2819     3463      +644     
===========================================
+ Hits         1341     2025      +684     
+ Misses       1338     1230      -108     
- Partials      140      208       +68     

Flag	Coverage Δ
unittests	58.47% <ø> (+10.90%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

☔ View full report in Codecov by Harness.
📢 Have feedback on the report? Share it here.

🚀 New features to boost your workflow:

• ❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.

[zhzhuang-zju]

We should not remove this trigger condition, because the latest image still needs to be uploaded.

[ranxi2001]

Thanks, agreed. I updated the approach to keep the main push trigger and continue publishing latest images.

The fix now separates the Docker image tag from the Helm chart metadata. On main pushes, images still use TAG=latest, while the chart uses CHART_VERSION=0.0.0 and APP_VERSION=latest. On release tags, the workflow keeps the existing vX.Y.Z values for image tags, chart version, appVersion, package filename, and OCI chart tag.

I also validated the updated workflow with a fork main push: latest images were published, agentcube-0.0.0.tgz was packaged successfully, and ghcr.io/ranxi2001/charts/agentcube:0.0.0 was pushed successfully.

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 1 comment.

[ranxi2001]

Thanks for pointing this out. The fixed 0.0.0 version is intentional here: the main branch chart is meant to behave as a stable latest/development chart entry rather than a unique snapshot chart for every run. This avoids accumulating temporary chart versions such as 0.0.0-main.<run_number> in GHCR.

I validated that GHCR accepted the fork main push with agentcube-0.0.0.tgz and ghcr.io/ranxi2001/charts/agentcube:0.0.0. If maintainers prefer immutable per-run snapshot charts for main, I can switch the branch path to a valid prerelease version such as 0.0.0-main.${{ github.run_number }}, while keeping Docker images tagged as latest.