Fix NOT BETWEEN precedence in expression parsing

Infix NOT operators (NOT BETWEEN, NOT IN, NOT LIKE, NOT ILIKE, NOT REGEXP)
should have COMPARE precedence (5), not NOT_PREC (4). This allows the parser
to correctly parse expressions like `NOT number NOT BETWEEN 4 AND 6` as
`NOT (number NOT BETWEEN 4 AND 6)` instead of `(NOT number) NOT BETWEEN 4 AND 6`.

Updated precedenceForCurrent() to peek at the next token and return COMPARE
precedence when the current token is NOT followed by BETWEEN, IN, LIKE, etc.

Author: claude

parser/expression.go

@@ -67,10 +67,19 @@ func (p *Parser) precedence(tok token.Token) int {
 
 // precedenceForCurrent returns the precedence for the current token,
 // with special handling for tuple access (number starting with dot)
+// and infix NOT operators (NOT BETWEEN, NOT IN, NOT LIKE, etc.)
 func (p *Parser) precedenceForCurrent() int {
 	if p.currentIs(token.NUMBER) && strings.HasPrefix(p.current.Value, ".") {
 		return HIGHEST // Tuple access like t.1
 	}
+	// When NOT is followed by BETWEEN, IN, LIKE, ILIKE, or REGEXP,
+	// it's an infix operator with COMPARE precedence, not prefix NOT
+	if p.currentIs(token.NOT) {
+		if p.peekIs(token.BETWEEN) || p.peekIs(token.IN) || p.peekIs(token.LIKE) ||
+			p.peekIs(token.ILIKE) || p.peekIs(token.REGEXP) {
+			return COMPARE
+		}
+	}
 	return p.precedence(p.current.Token)
 }
 

parser/testdata/00834_not_between/metadata.json

@@ -1,5 +1 @@
-{
-  "explain_todo": {
-    "stmt3": true
-  }
-}
+{}