Lint rule: maximum line length

[roxspring]

Implement a lint rule that reports lines exceeding a configurable maximum length.

Scope

• Configurable maximum (default: 120 characters)
• Operates on the raw source lines of each .md file
• Reports file path and line number for each violation
• Optionally skips lines inside fenced code blocks (configurable, default: skip)
• Optionally skips front matter (configurable, default: skip)

Example violation

guide/editor.md:34: line length 147 exceeds maximum 120

Acceptance criteria

• Lines within limit: no violation
• Lines exceeding limit: violation reported with line number
• Lines inside fenced code blocks skipped by default
• Front matter lines skipped by default