CCM-14750: Add single-release release-check flow - #295

Description

This slice delivers the first end-to-end release-check flow for a single release.

It includes:

• orchestration that combines release inputs with Jira reads
• comparison logic for a single release/tag
• reporting of mismatches so missing or incorrect ticket tracking becomes visible
• tests covering the initial end-to-end behaviour

Context

The governance problem we are solving is whether the tickets represented in a shipped release are the same tickets that Jira says were released. This PR is the first slice that answers that question for one release at a time.

It stops short of multi-release handling and any automated fix path so that the review can stay focused on the correctness of the core comparison model.

Why this is a separate slice

Once reviewers are happy with the single-release flow, the higher slices can extend the same behaviour across multiple releases and optional remediation workflows without reopening the foundational comparison decisions.

Validation

• package install
• lint
• typecheck
• unit tests

Sensitive Information Declaration

• I confirm that neither PII/PID nor sensitive data are included in this PR and the codebase changes.