Migrate config + caches to `$CLAUDE_PLUGIN_DATA` (`~/.claude/plugins/data/`) per official plugin spec

[qhuang20]

Hi! Love the plugin — using it daily.

Noticed claude-hud currently writes its runtime data directly under ~/.claude/plugins/claude-hud/:

• config.json
• config-cache/
• transcript-cache/

The official Claude Code Plugins reference introduces a standardized location:

Persistent data directory
The ${CLAUDE_PLUGIN_DATA} directory resolves to ~/.claude/plugins/data/{id}/, where {id} is the plugin identifier with characters outside a-z, A-Z, 0-9, _, - replaced by -. For a plugin installed as formatter@my-marketplace, the directory is ~/.claude/plugins/data/formatter-my-marketplace/.

For claude-hud that would be ~/.claude/plugins/data/claude-hud-claude-hud/, and the env var $CLAUDE_PLUGIN_DATA is auto-injected so the plugin doesn't need to hardcode it.

Benefits of migrating:

• Auto-cleanup on uninstall (with --keep-data opt-out)
• Counted in /plugin UI's data-size display
• Future-proof against any auto-cleanup of unknown top-level dirs in ~/.claude/plugins/
• Plays nicely with multi-account setups via CLAUDE_CONFIG_DIR (related: Support CLAUDE_CONFIG_DIR for multi-account setups #274)

Suggested migration path (one-time, in startup code):

const dataDir = process.env.CLAUDE_PLUGIN_DATA
  ?? path.join(os.homedir(), '.claude/plugins/claude-hud');  // fallback

// On first run after upgrade, if old path exists and new one doesn't, move it:
const oldPath = path.join(os.homedir(), '.claude/plugins/claude-hud');
if (fs.existsSync(oldPath) && !fs.existsSync(dataDir) && oldPath !== dataDir) {
  fs.renameSync(oldPath, dataDir);
}

Happy to send a PR if you'd like.

Thanks!

— @qhuang20

[UnpxreTW]

Migrating to $CLAUDE_PLUGIN_DATA is definitely the right direction, but there are a few points that might need clarification first:

StatusLine subprocess environment variable inheritance

The HUD works by Claude Code executing a subprocess via statusLine.command (bash -c '...') every ~300ms to render the display. This subprocess needs to read config.json.

It's unclear whether Claude Code injects $CLAUDE_PLUGIN_DATA into the environment when executing the statusLine command. If it doesn't, the subprocess won't be able to locate the new path, which could break the migration.

Impact on existing users

• Updating the plugin without re-running setup → config.json stays at the old path, but the new code looks at the new path → configuration lost
• The statusLine bash command already saved in settings.json also hardcodes the old path — users would need to re-run setup for the change to take effect
• Users with multi-account setups via CLAUDE_CONFIG_DIR — the migration logic would need to correctly handle the base path

Scope of changes

The core code change is small (getHudPluginDir() + one fallback line), but 3 command files with ~14 hardcoded path references would also need updating, along with README and other docs.

If the $CLAUDE_PLUGIN_DATA injection behavior in statusLine subprocesses can be confirmed first, the implementation should go smoothly from there.