Add a skill package system where each skill is a directory with a skill.yaml
manifest and prompt markdown files. Skills support /command triggers, scoped
config overrides (temperature, max_tokens, tool filtering), chain dependencies
with cycle-safe resolution, and a finish_skill completion signal.
Includes four built-in skills: explore, brainstorm, write-document, and plan.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
push_screen_wait requires a worker context, but on_mount is a plain
lifecycle callback. Extract session resume logic into a @work-decorated
method so the modal can be awaited without triggering NoActiveWorker.
The App base class uses _registry (WeakSet) for DOM node tracking.
Our _registry attribute for the tool registry was shadowing it with None,
causing a TypeError during shutdown.
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
