ab7e00a217
Add CL/SQL-style symbol quoting using pipe delimiters for formula identifiers. This allows category and item names that collide with keywords (WHERE, SUM, IF, etc.) or contain special characters (parens, operators, spaces) to be used unambiguously in formulas: |WHERE| + |Revenue (USD)| SUM(|Net Revenue| WHERE |Region Name| = |East Coast|) Pipes produce Token::Ident (same as bare identifiers), so they work everywhere: expressions, aggregates, WHERE clauses. Double-quoted strings remain Token::Str for backward compatibility. Also updates split_where and parse_where to skip/strip pipe delimiters. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>