feat: supplied base-ref

[vaernion]

No description provided.

[Copilot]

Pull Request Overview

This PR adds support for supplying an explicit base reference for Git comparison, allowing users to skip the automatic workflow run lookup and directly specify a commit SHA, branch, tag, or remote ref as the comparison base.

• Added base-ref input parameter that accepts Git references and bypasses workflow run lookup when provided
• Enhanced shell script robustness by converting single brackets to double brackets throughout
• Updated documentation and test workflows to demonstrate the new base-ref functionality

Reviewed Changes

Copilot reviewed 4 out of 4 changed files in this pull request and generated 3 comments.

File	Description
action.yml	Adds base-ref input and implements early exit logic when base-ref is provided, plus shell syntax improvements
README.md	Documents the new base-ref parameter and provides usage examples
.github/workflows/test.yml	Updates branch name and fixes output reference inconsistency
.github/workflows/test-basic.yml	Demonstrates base-ref usage and updates branch/output references

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[mkilgus-at]

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