util-ustaggerlisted

# Util US Tagger Tag untagged items in PRD.md files with unique 9-character ID codes and validate no duplicates. Covers User Stories, Non Functional Requirements, Constraints, References, and Test instructions. ## Version Gate Before starting any work, resolve the application folder first (see Input Resolution below), then check `CHANGELOG.md` in the application folder (`<app_folder>/CHANGELOG.md`): 1. If `<app_folder>/CHANGELOG.md` does not exist, skip this check (first-ever execution for this application). 2. If `<app_folder>/CHANGELOG.md` exists, scan all `## vX.Y.Z` headings and determine the **highest version** using semantic versioning comparison. 3. Compare the requested version against the highest version: - If requested version **>=** highest version: proceed normally. - If requested version **<** highest version: **STOP immediately**. Print: `"Version {requested} is lower than the current application version {highest} recorded in <app_folder>/CHANGELOG.md. Execution rejected."` Do NOT proceed with any work. ## Input Resolution This skill requires two mandatory arguments: `<application>` and `<version>`. | Argument | Required | Description | |----------|----------|-------------| | `<application>` | Yes | Application name — matched against root-level application folders | | `<version>` | Yes | Version label (e.g., `v1.0.3`). Recorded for traceability but all items are tagged regardless of version. | ### Application Folder Resolution 1. List root-level a