Function migrateLooseAssets

apps/desktop/src/main/vault.ts:1228–1304

(
  root: string
)

 * open. Returns the moved (assets-relative) and skipped (source) paths.
 */
export async function migrateLooseAssets(
  root: string
): Promise<{ moved: string[]; skipped: string[] }> {
  const moved: string[] = []
  const skipped: string[] = []
  const assetsAbs = path.join(root, ASSETS_DIR)

  const moveIntoAssets = async (srcRel: string): Promise<void> => {
    const destRel = `${ASSETS_DIR}/${path.basename(srcRel)}`
    if (toPosix(srcRel) === destRel) return
    const destAbs = resolveSafe(root, destRel)
    try {
      await fs.access(destAbs) // a same-named asset already exists — don't clobber/rename
      skipped.push(toPosix(srcRel))
      return
    } catch {
      /* destination free */
    }
    await fs.mkdir(assetsAbs, { recursive: true })
    await fs.rename(resolveSafe(root, srcRel), destAbs)
    moved.push(destRel)
  }

  // 1. Loose asset files sitting directly at the vault root.
  //
  // Skip this for a vault managed by another app — an `.obsidian/` directory
  // marks an Obsidian vault. Those loose root files (`.canvas`, images, PDFs,
  // anything) are the user's own, not ZenNotes' legacy attachments, and
  // silently relocating them into `assets/` surprised users who pointed
  // ZenNotes at an existing Obsidian vault (#202). The legacy ZenNotes
  // attachment dirs below never exist in such a vault, so they stay safe.
  let isExternalVault = false
  try {
    await fs.access(path.join(root, '.obsidian'))
    isExternalVault = true
  } catch {
    /* not an Obsidian vault */
  }
  if (!isExternalVault) {
    let rootEntries: Dirent[] = []
    try {
      rootEntries = await fs.readdir(root, { withFileTypes: true })
    } catch {
      rootEntries = []
    }
    for (const entry of rootEntries) {
      if (entry.name.startsWith('.') || !entry.isFile()) continue
      if (entry.name.toLowerCase().endsWith('.md')) continue // a note
      if (databaseCsvPathFor(entry.name) || isDatabaseInternalPath(entry.name)) continue // a database
      await moveIntoAssets(entry.name)
    }
  }

  // 2. Files in the legacy attachment dirs, then drop the dir if it empties.
  for (const dir of LEGACY_ATTACHMENTS_DIRS) {
    let entries: Dirent[]
    try {
      entries = await fs.readdir(path.join(root, dir), { withFileTypes: true })