v0.6.5

Added

• Accepted .field and .0 shorthand expressions in #[error("...")] format
  argument lists, resolving them against struct and variant fields without
  moving the original values.

Changed

• The format argument resolver now tracks whether it operates on a struct or a
  destructured enum variant, allowing field shorthands to reuse local bindings
  and honour pointer formatting requirements.

Tests

• Added trybuild pass cases covering named, positional and implicit arguments,
  formatter path handlers and the new field shorthand expressions.
• Introduced compile-fail fixtures for duplicate argument names, mixing
  implicit placeholders after explicitly indexed ones and combining
  transparent with fmt handlers.
• Extended the runtime error_derive suite with assertions exercising the
  shorthand field accessors.