fix: correct returnsuccess redis status key

[Luzijano]

Summary

• Fix the returnsuccess Redis status set key from brdigeops:returnsuccess to bridgeops:returnsuccess.
• Add regression tests covering the bridge operation Redis namespace and the returnsuccess mapping.

Why

The misspelled Redis key can split returned-success operations into a different namespace than the other bridge operation status sets, making successful return tracking inconsistent.

Validation

• RED before fix: go test ./config failed on returnsuccess Redis key = "brdigeops:returnsuccess".
• GREEN after fix: go test ./config
• Regression suite: go test ./...

Bounty context

This is submitted as a small reliability/test-coverage improvement under the Bitgesell bounty/improvement program and aligns with #3.

AI assistance was used to inspect the issue, write the regression tests, and validate the fix.

[MyTH-zyxeon]

Review assist for maintainers:

This is a narrow bridge reliability fix: returnsuccess currently points at the misspelled Redis set key brdigeops:returnsuccess, while the patch aligns it with the rest of the bridge operation namespace as bridgeops:returnsuccess. The new config tests cover both the shared bridgeops: namespace invariant and the exact returned-success mapping.

Suggested merge checks:

• Run go test ./config and the repo's normal go test ./... target from the PR body.
• Confirm whether any existing Redis deployments may already contain the misspelled brdigeops:returnsuccess set; if so, decide whether a small migration/cleanup note is needed for stale historical entries.
• Verify status writers and readers all use RedisStatusSets["returnsuccess"], so this one map change fixes both insertion and lookup paths consistently.

I do not see signing, wallet/key, RPC endpoint, live-chain, or bridge transaction-flow changes in this patch as written; the acceptance criterion is that returned-success operations no longer get split into a misspelled Redis namespace, with regression tests preventing the key from drifting again.