…#599)

* Improve loader performance

* Avoid quadratic entry accumulation in the parser

* Add a literal fast path to the value parser

* Consume lexer tokens lazily when parsing values

* Simplify splitting entries into parts

* Add an ASCII fast path for name validation

* Avoid closures when wrapping preg results

* Tidy up doc comments

* Test on PHP 8.6

* Update composer.json

* Upgrade phpstan

* Validate variable names with the u modifier instead of the (*UTF8) verb

* Add tests pinning invalid UTF-8 name rejection

* Strip the export prefix and name quotes with byte operations

…ll byte (phpdotenv#603)

* Add a value factory for pre-computed characters and offsets

* Accumulate parsed value chunks in linear time

…nv#605)

)

* Cap the value context in parse error messages

* Surface invalid regular expressions in allowedRegexValues

* Accept encoding names case-insensitively and via aliases

* Clarify the empty-file-path and repository builder messages

* Escape control bytes in parse error messages

* Run the test suite with the unpolyfilled mbstring functions disabled

* Fix the entry test helpers to honour the expected name

* Cover interpolation following multibyte text

* Cover the nested-variable anchor with a bare dollar and an escaped reference

* Cover indented comments

* Pin UTF-16 and UTF-32 files with a byte order mark

* Strengthen the immutable load test to assert the written state

…les (phpdotenv#609)

* Document nested variable resolution rules

* Document comment and quoting behaviour

* Document escape sequences in double-quoted values

* Correct the loader tagline and validation examples

* Document multiline values, file options and parse-versus-load