CP-41274: Add local semver action and update release workflow

[ajzaff]

Summary

• Copies the semver action locally to .github/actions/semver/ to avoid external dependencies in this public repository
• Updates the release workflow to use the local action
• Updates README example to use a direct version input instead of an external semver action

Test plan

• Trigger the release workflow manually and verify version detection works
• Confirm nextVersion output is populated correctly for the release and tagging steps

🤖 Generated with Claude Code

[greptile-apps]

Greptile Summary

Replaces the third-party flatherskevin/semver-action@v1 with the internal Cloudzero/ops-github-actions/.github/actions/common/semver@v2 in both the release workflow and the README example, reducing supply-chain exposure with no interface changes.

Confidence Score: 5/5

Safe to merge — minimal, focused swap with no functional changes.

Both changed lines are identical single-line replacements of an action reference; inputs, outputs, and surrounding workflow logic are untouched. No logic bugs, security concerns, or custom rule violations apply to this change.

No files require special attention.

Important Files Changed

Filename	Overview
.github/workflows/release.yml	Single-line swap of third-party semver action for internal Cloudzero equivalent; inputs/outputs unchanged.
README.md	Documentation example updated to match the new internal action reference, keeping it in sync with the actual workflow.

_{Reviews (2): Last reviewed commit: "Replace flatherskevin/semver-action with..." | Re-trigger Greptile}