4.1.5

• Fixes a 500 error when PATCHing a document whose YAML frontmatter contains
  values valid in Obsidian but invalid per strict YAML 1.2 (e.g. an unquoted
  colon in a scalar). The REST PATCH endpoints and MCP vault_patch tool now
  return HTTP 400 with error code 40005 (InvalidFrontmatter) so callers know
  the document's frontmatter needs to be fixed.
• Bumps markdown-patch from 1.0.0 to 1.1.0, which adds FrontmatterParseError,
  fixes silent ignoring of rejectIfContentPreexists for application/json table
  content, handles empty frontmatter blocks, and fixes a bare Error thrown on
  type mismatch.