feat: extend probabilistic tools with field selection and complementary sampling

[jo-cube]

• Add literal-delimited field selection to hll and heavy, with shared input handling across probabilistic tools.
• Add sample --invert for complementary rate samples, including stable field-based splits.
• Preserve JSON value types and object key ordering in card.
• Reduce unnecessary work and allocations in card, heavy, and rdbsh.
• Add focused tests, benchmarks, CLI smoke checks, and documentation.