Module parser/rules/block/utils

Shared utilities used by block-level parser rules.

This module provides the core building blocks that most block rules depend on:

• canApplyBlockRule -- fast pre-check for whether a rule's start tokens match the current token.
• parseBlocksUntil -- the main block-level content parser that iterates rules until a close condition is met (used by div, collapsible, tabview, iftags, align, etc.).
• parseInlineContentUntil -- similar to parseBlocksUntil but without paragraph wrapping, used for div_ paragraph-strip mode.
• parseAttributes / parseAttributesRaw -- attribute parsers for block opening tags (with and without safety filtering).
• createBlockEndCondition -- factory for close-condition predicates.

Re-exports filterUnsafeAttributes and parseBlockName from the shared ../utils module for backward compatibility.