feat: support pattern strategy

[mdonnalley]

• Support schema generation when oclif.commands is a pattern-strategy object instead of a string
• Disallow schema generation when CLI is a single command CLI or uses explicit command strategy

Depends on oclif/core#945

@W-15005785@

[mshanemc]

minor perf comment...probably doesn't matter in a dev plugin like this.

[mshanemc]

readdirSync has the withFileTypes option so you don't have to statSync them all to do isDir.

Can you also make a comment so that when we get everything to node20, we can just use the recursive option (it was backported to 18.17)

[mshanemc]

export const getAllFiles = (dirPath: string, ext: string, allFiles: string[] = []): string[] =>
  safeReadDirSync(dirPath)
    .flatMap((f) =>
      f.isDirectory() ? getAllFiles(path.join(dirPath, f.name), ext, allFiles) : path.join(dirPath, f.name),
    )
    .filter((f) => f.endsWith(ext))

const safeReadDirSync = (dirPath: string): fs.Dirent[] => {
  try {
    return fs.readdirSync(dirPath, {withFileTypes: true})
  } catch {
    return []
  }
}