Fix repeat with named dataset arguments

[drewmt]

What:

• Bug Fix
• New Feature

Description:

repeat() prepends its iteration value to the data provider arguments and later moves it to the end before invoking the test. With named dataset arguments, appending that value as a positional argument causes PHP to throw Cannot use positional argument after named argument.

This keeps the existing positional behavior, maps the iteration value to the next test parameter when named arguments are used, and omits it when the test does not accept an iteration parameter. Regression coverage includes both named datasets with and without the repeat iterator.

The aggregate visual snapshots are updated for the eight additional repeated executions and twenty assertions.

Related:

Fixes #1767

Validation:

• php bin/pest tests/Features/Repeat.php --compact — 142 tests, 327 assertions
• composer test:lint
• composer test:type:check
• Type coverage — 100%

The full local matrix was also attempted. Its remaining failures are limited to the existing macOS-specific Backtrace expectation and platform-dependent visual aggregate counts; the focused behavior, lint, static analysis, and type coverage pass.