Rule fix function

v4 had RuleSeed.fix() and a --fix flag; no bundled rule implemented it, so --fix did nothing for built-in rules. v5 uses a per-violation fix callback on report(). Rules without fix are unchanged.

context.report({
  scope: node,
  message: 'Tag name should be lowercase',
  fix: fixer => fixer.replaceText({ startOffset: nameOffset, raw: node.rawName }, node.rawName.toLowerCase()),
});

The callback runs only when fix=true is passed to verification (CLI --fix).

IRuleFixer: replaceText, replaceRange, insertBefore, insertAfter, remove, removeRange. Token shape is { startOffset, raw }. Return an array of TextEdit for atomic multi-edits (overlap skips the whole group).

Helpers in @markuplint/rules: removeAttr, removeAttrValue.

Overlapping fixes: apply a pass, skip overlaps, re-parse, repeat (cap 10).

Built-in rules with fix in v5: case-sensitive-tag-name, case-sensitive-attr-name, attr-value-quotes, no-boolean-attr-value, no-default-value, no-duplicate-attr, no-ineffective-attr, no-orphaned-end-tag, no-consecutive-br, attr-order, head-element-order.

Types: IRuleFixer, TextEdit, FixToken from @markuplint/ml-config.