Plugin UI contributions

Plugins declare ui_contributions in planeai-plugin.json. Each contribution has a safe per-plugin id, user-facing label, placement, and self-contained ESM entrypoint. Supported placements are sidebar.header, sidebar.navigation, sidebar.footer, and main-pane. Sidebar contributions may use order; main panes may declare an optional portable Mod+… shortcut and are always available through Cmd+K while running.

An entrypoint default-exports { mount(root, context) { return dispose; } }. root is an isolated ShadowRoot. Context provides plugin metadata, contribution metadata, scoped sidecar RPC through host.call, and host.navigation.open(pluginId, contributionId) / host.navigation.close(). Contributions may navigate across running plugins to declared main panes.

Use inherited PlaneAI CSS tokens such as --color-t1, --color-panel, and --color-border; do not depend on PlaneAI DOM or Tailwind classes. Bundles must be self-contained: relative imports and package asset graphs are not loaded in v1. Rebuild and reinstall an immutable local package to pick up manifest or UI changes.