async function remove (href) {
  let existing = await get(href)
  if (!existing) return
  let urlp = new URL(existing.bookmarkUrl)
  let drive = await drives.getOrLoadDrive(urlp.hostname)
  await drive.pda.unlink(urlp.pathname)
  if (existing.pinned) await pinsAPI.remove(existing.href)
}
@param {string} href
@returns {Promise<void>}