1.0.3

Fix plugin review findings for 1.0.3

- Stop detaching the tracker leaf in onunload and reuse an existing
  leaf in activateView instead of detaching and recreating it
- Await revealLeaf and raise minAppVersion to 1.7.2 to match it
- Rename the open command to "open-view" / "Open view" so the plugin
  id and name are not repeated
- Treat loadData results as unknown and guard with isRecord
- Replace async event/modal callbacks with explicitly handled promises
- Remove the settings tab heading and the unused builtin-modules dep
- Replace column-gap and display: contents in the calendar layout with
  grid placement for broader renderer support