kata-updating

<objective>
Check for Kata updates, install if available, and display what changed.

Provides a better update experience than raw `npx @gannonh/kata` by showing version diff and changelog entries.
</objective>

<process>

<step name="get_installed_version">
Read installed version:

```bash
cat ~/.claude/kata/VERSION 2>/dev/null
```

**If VERSION file missing:**
```
## Kata Update

**Installed version:** Unknown

Your installation doesn't include version tracking.

Running fresh install...
```

Proceed to install step (treat as version 0.0.0 for comparison).
</step>

<step name="check_latest_version">
Check npm for latest version:

```bash
npm view @gannonh/kata version 2>/dev/null
```

**If npm check fails:**
```
Couldn't check for updates (offline or npm unavailable).

To update manually: `npx @gannonh/kata --global`
```

STOP here if npm unavailable.
</step>

<step name="compare_versions">
Compare installed vs latest:

**If installed == latest:**
```
## Kata Update

**Installed:** X.Y.Z
**Latest:** X.Y.Z

You're already on the latest version.
```

STOP here if already up to date.

**If installed > latest:**
```
## Kata Update

**Installed:** X.Y.Z
**Latest:** A.B.C

You're ahead of the latest release (development version?).
```

STOP here if ahead.
</step>

<step name="show_changes_and_confirm">
**If update available**, fetch and show what's new BEFORE updating:

1. Fetch changelog (same as fetch_changelog step)
2. Extract entries between installed and latest versions
3. Display preview and ask for confirmation:

```
## Kata Update Available

**Installed:** 1.5.10
**Latest:** 1.5.15

### What's New
────────────────────────────────────────────────────────────

## [1.5.15] - 2026-01-20

### Added
- Feature X

## [1.5.14] - 2026-01-18

### Fixed
- Bug fix Y

────────────────────────────────────────────────────────────

⚠️  **Note:** The installer performs a clean install of Kata folders:
- `~/.claude/commands/kata/` will be wiped and replaced
- `~/.claude/kata/` will