- Remove all symlink creation and resolution in favor of plain files
- currentvault file now contains relative path like "vaults.d/default"
- current-unlocker file now contains relative path like "unlockers.d/passphrase"
- current version file now contains relative path like "versions/20231215.001"
- Simplify path resolution to just read file contents and join with parent dir
- Update all tests to read files instead of using os.Readlink