v1.2.1 — honor config.vendor-dir

Fixed

• InstalledPackageReader now honors composer.json's
  config.vendor-dir override. Consumers with a non-default vendor
  directory (e.g. CWMLivingWord and Proclaim both ship with
  "vendor-dir": "libraries/vendor") had the cross-package machinery
  silently degrade to zero deps — installed.json was being looked up
  at <project>/vendor/composer/installed.json regardless of the
  configured location. cwm-link and cwm-verify --target dev now
  resolve installed.json against the actual vendor dir, so the CWM
  dependencies section appears as designed.