v0.19.0

Added

• PHP 8.6 partial function application (early support) — PhpVersion::Php86 added; the parser now understands the ? and bare ... call-argument placeholders (e.g. foo(1, ?, 3), foo(1, ...), foo(s: ?), stuff(1, a: 5, ...)) from the Partial Function Application RFC. Placeholders are rejected in new expressions, matching the RFC. Default parse target stays Php85 since PHP 8.6 hasn't shipped yet (php-rs-parser, php-ast, php-printer).