fix: dashboard controller support for multi-channel mode

The Indiekit backend UI was broken when using channels array
because the dashboard controller only checked for channelId/channelHandle.

Now uses getPrimaryChannel() helper to extract the first channel
from either single-channel or multi-channel configuration.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

CLAUDE.md

@@ -0,0 +1,44 @@
+# CLAUDE.md
+
+This file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.
+
+## Project Overview
+
+This is an Indiekit plugin that adds a YouTube channel endpoint. It displays latest videos and live streaming status from a YouTube channel, with both an admin dashboard and public JSON API endpoints.
+
+## Development
+
+This is an ESM module with no build step. Install dependencies with `npm install`.
+
+No test suite is configured. Testing requires a running Indiekit instance with valid YouTube API credentials.
+
+## Architecture
+
+**Plugin Entry Point** (`index.js`):
+- Exports a `YouTubeEndpoint` class that Indiekit loads as a plugin
+- Registers protected routes (admin dashboard) and public routes (JSON API)
+- Stores configuration in `Indiekit.config.application.youtubeConfig` for controller access
+
+**YouTube API Client** (`lib/youtube-client.js`):
+- Handles all YouTube Data API v3 interactions
+- Implements in-memory caching with configurable TTL
+- Uses uploads playlist method for quota efficiency (2 units) instead of search (100 units)
+- Channel info cached for 24 hours; videos cached per `cacheTtl` option
+
+**Controllers** (`lib/controllers/`):
+- `dashboard.js` - Admin page rendering, cache refresh
+- `videos.js` - `/api/videos` JSON endpoint
+- `channel.js` - `/api/channel` JSON endpoint
+- `live.js` - `/api/live` JSON endpoint with efficient vs full search modes
+
+**Views/Templates**:
+- `views/youtube.njk` - Admin dashboard template (Nunjucks)
+- `includes/@indiekit-endpoint-youtube-widget.njk` - Widget component
+
+## API Quota Considerations
+
+YouTube Data API has a 10,000 units/day default quota:
+- `channels.list`, `playlistItems.list`, `videos.list`: 1 unit each
+- `search.list`: 100 units (used only for full live status check with `?full=true`)
+
+The plugin uses the playlist method by default for quota efficiency.