Memory Metadata Search

This adds structured filtering to Basic Memory's search. Instead of searching note content, you query custom frontmatter fields like status, priority, or confidence scores using equality, range, and array operators. Any YAML key you add to frontmatter becomes queryable automatically without configuration. The syntax is straightforward JSON filters passed to search_notes: {"confidence": {"$gt": 0.7}} or {"priority": {"$in": ["high", "critical"]}}. You can combine metadata filters with text search or use them alone. Most useful when you've been disciplined about adding custom fields to your notes and need to find things by their properties rather than their content. Works with dot notation for nested fields and has tag shortcuts for common cases.