test: fix hedge-walk mock queues so cap logic is actually exercised

[kunalrbhatia]

Summary

Fix the hedge-walk unit tests added in PR #118 — mock queues were ordered incorrectly, so the PE-hedge walk never exercised the cap logic.

Why

The 3 tests added with PR #118 used .mockResolvedValue(false) (a default) interleaved with .mockResolvedValueOnce() entries. Jest consumes once-queue values in registration order BEFORE falling back to the default — so the PE hedge "succeeded" on its first attempt (consuming the value meant for CE Sell) and the walk/cap code path was never tested. Result: tests expected 8 calls, got 4, and CI on development was red after the docs PR #119 merged.

Change

Rewrote the 3 tests with fully deterministic mockResolvedValueOnce queues matching the exact call sequence (CE hedge + 6 PE attempts + 2 sells = 9 calls; CE-walk variant = 6; CE-cap variant = 9).

Verification

• Jest: all 3 tests pass, expecting exact call counts (9/6/9).
• Full suite green (coverage threshold 80% restored).