BlueBubbles plugin

Use this skill when working on the BlueBubbles channel plugin.

Layout

• Extension package: extensions/bluebubbles/ (entry: index.ts).
• Channel implementation: extensions/bluebubbles/src/channel.ts.
• Webhook handling: extensions/bluebubbles/src/monitor.ts (register via api.registerHttpHandler).
• REST helpers: extensions/bluebubbles/src/send.ts + extensions/bluebubbles/src/probe.ts.
• Runtime bridge: extensions/bluebubbles/src/runtime.ts (set via api.runtime).
• Catalog entry for onboarding: src/channels/plugins/catalog.ts.

Internal helpers (use these, not raw API calls)