kata-whats-new

<objective>
Display changes between installed version and latest available version.

Shows version comparison, changelog entries for missed versions, and update instructions.
</objective>

<process>

<step name="get_installed_version">
Read installed version from VERSION file (checking plugin context first):

```bash
if [ -n "$CLAUDE_PLUGIN_ROOT" ]; then
  cat "$CLAUDE_PLUGIN_ROOT/VERSION" 2>/dev/null
fi
```

**If VERSION file missing:**
```
## Kata What's New

**Installed version:** Unknown

Your installation doesn't include version tracking.

**To reinstall:**
`/plugin install kata@kata-marketplace`
```

STOP here if no VERSION file.
</step>

<step name="fetch_remote_changelog">
Fetch latest CHANGELOG.md from GitHub:

Use WebFetch tool with:
- URL: `https://raw.githubusercontent.com/gannonh/kata/refs/heads/main/CHANGELOG.md`
- Prompt: "Extract all version entries with their dates and changes. Return in Keep-a-Changelog format."

**If fetch fails:**
Fall back to local changelog:
```bash
cat "$CLAUDE_PLUGIN_ROOT/CHANGELOG.md" 2>/dev/null
```

Note to user: "Couldn't check for updates (offline or GitHub unavailable). Showing local changelog."
</step>

<step name="parse_versions">
From the remote (or local) changelog:

1. **Extract latest version** - First `## [X.Y.Z]` line after `## [Unreleased]`
2. **Compare with installed** - From VERSION file
3. **Extract entries between** - All version sections from latest down to (but not including) installed

**Version comparison:**
- If installed == latest: "You're on the latest version"
- If installed < latest: Show changes since installed version
- If installed > latest: "You're ahead of latest release (development version?)"
</step>

<step name="display_output">
Format output clearly:

**If up to date:**
```
## Kata What's New

**Installed:** 1.4.26
**Latest:** 1.4.26

You're on the latest version.

[View full changelog](https://github.com/gannnonh/kata/blob/main/CHANGELOG.md)
```

**If updates available:**
```
## Kata What