Function extractQueryEntities

Extract candidate entity strings from a query. Matches the Mem0-v3-style regex extractor used at ingest time so query and fact entities use the same canonicalization.

Captures:

• Capitalized words ≥ 3 characters (proper nouns: "Berlin", "Docker", "TypeScript")
• Double-quoted strings ("hello world")
• Single-quoted strings ('like this')

Returns deduplicated entity strings preserving original casing (case-sensitive comparison happens upstream).