Add explicit tests for Rejection Pass-Through and Value Extraction Consistency

[Copilot]

Addresses the two TODO items in the Property Verification Strategy: CLAIM 6 (Rejection Pass-Through) had no isolated test proving SettledLeft items skip transformation, and CLAIM 7 (Value Extraction Consistency) lacked explicit tests defining the semantic contract between getValues(), getAllValues(), and toArray().

Rejection Pass-Through (rejectionPassThrough.test.ts — 5 tests)

• Asserts transformFn is never called on already-rejected items
• Validates currentRejection: false for inherited errors vs true for errors thrown in current step
• Verifies index, transformStep, and errLookup callback args are preserved correctly on pass-through

const transformFn = jest.fn(async (x: string) => x.toUpperCase());
const result = await fn_a1f9a({
  item: { status: 'rejected', reason: new Error('previous error') },
  index: 0, array: [rejectedItem], transform: transformFn,
});
expect(transformFn).not.toHaveBeenCalled();
expect(result).toHaveProperty('currentRejection', false);

Value Extraction Consistency (valueExtraction.test.ts — 13 tests)

• getValues() — returns only fulfilled values; empty array when all rejected
• getAllValues() — preserves array length; NULL_SYMBOL at rejected positions
• toArray() — full settled metadata (status, index, transformStep)
• Cross-method invariants:
  • getValues().length <= getAllValues().length
  • toArray().length === getAllValues().length
  • NULL_SYMBOL positions in getAllValues() align with status: 'rejected' in toArray()
  • getValues() matches the fulfilled subset of toArray()

Baseline 253 → 271 tests, all passing.