fix(oracle): parse boolean postfix checks

[rebelice]

Summary

• Parse Oracle postfix predicates (IS, IN, BETWEEN, LIKE) inside the expression precedence loop so low-precedence AND/OR can continue after them.
• Fix LikeExpr source locations to include the left operand.
• Add regression coverage for CHECK (... IS NULL OR ...) and full LIKE NodeLoc ranges.

Test Plan

• go test ./oracle/... -count=1