v0.6.0

Added

• Recognised empty placeholder bodies ({} / {:?}) as implicit positional
  identifiers, numbering them by appearance and exposing the new
  TemplateIdentifier::Implicit variant in the template API.
• Propagated the implicit identifier metadata through
  template_support::TemplateIdentifierSpec, ensuring derive-generated display
  implementations resolve tuple fields in placeholder order.

Fixed

• Preserved TemplateError::EmptyPlaceholder diagnostics for whitespace-only
  placeholders, matching previous error reporting for invalid bodies.

Tests

• Added parser regressions covering implicit placeholder sequencing and the
  whitespace-only error path.