fix: apply CEI ordering to auction bids

[sirakinb]

Summary

• persist bid records, highest bid, bidder deposit records, prior-deposit cleanup, and auction winner state before token transfers in place_bid
• move new-bid escrow and previous-winner refund after the auction effects are committed
• add coverage for bidder deposit records so the outbid cleanup is asserted

Tests

• cargo fmt -p pulsar-auction-engine --check
• cargo +1.91.1 test -p pulsar-auction-engine

Refs #553

[sirakinb]

Rebased this branch onto current main and resolved the conflict by keeping all bid/highest/winner/bidder storage effects before any token transfer.

Verification after rebase:

• cargo +1.91.1 fmt -p pulsar-auction-engine --check
• git diff --check
• cargo +1.91.1 test -p pulsar-auction-engine (21 passed)

Note: the Soroban test run rewrote local snapshot artifacts; I restored that generated churn and did not include it in the branch.