Lex queries now support:
- "exact phrase" - quoted exact matching (no prefix)
- -term or -"phrase" - exclude from results
- term1 OR term2 - match either term
Semantic queries (vec/hyde) validate and reject these operators
with helpful error messages.
Examples:
performance -sports → matches "performance" excluding "sports"
"machine learning" → exact phrase match
auth OR authentication → matches either term