Module parser/rules/block/module/include

Include directive resolution for Wikidot's [[include page]] syntax.

The include system performs text-level macro expansion before parsing. Each [[include page | var=value]] directive is replaced with the fetched page's content (after variable substitution), allowing block structures like [[div]] to span across include boundaries.

Supports:

• Same-site includes: [[include page-name]]
• Cross-site includes: [[include :site-name:page-name]]
• Variable substitution: [[include page | key=value]] replaces {$key} in the included content
• Iterative expansion with configurable iteration limit (Wikidot-compatible)