Add adversarial test that a new operator fully supersedes the prior operator's authority

[Jagadeeshftw]

📌 Description

set_operator(operator) appoints a single operator address (admin-only, per the README's table). When the admin appoints a new operator, the previous operator's ability to call pause/unpause must be fully revoked in the same transaction — there should be no window, and no code path, where both the old and new operator addresses remain independently authorized.

🧩 Requirements and context

• Add a test: appoint operator A, appoint operator B (replacing A), then assert A can no longer call pause/unpause (rejected) while B can.
• Confirm operator()/is_operator(address) reads reflect only the current operator, never a stale prior one.
• No functional change expected unless the test uncovers a real gap.

🛠️ Suggested execution

• Add the adversarial replace-operator test to src/test.rs using mock_auths to attempt the call as the old operator post-replacement.
• Fix set_operator/is_operator in src/lib.rs if a gap is found.

✅ Acceptance criteria

• A superseded operator can no longer call pause/unpause.
• is_operator never reports a stale prior operator as current.
• Regression test locks in the guarantee.

🔒 Security notes

Directly verifies there's no privilege-retention window when the operator role changes hands.

📋 Guidelines

• Minimum 95% test coverage
• Clear documentation
• Timeframe: 96 hours

[GBOYEE]

Hi team \u2014 I'd like to take this on (Add adversarial test that a new operator fully supersedes the prior...). I'll implement it to spec and add tests. Happy to submit a PR for this once the bot assigns it.

[grantfox-oss]

🦊 GrantFox — @mordabdul1 has been assigned to this issue as part of the Official Campaign | FWC26 campaign!

Next steps:

1. Open a Pull Request referencing this issue (e.g., Closes #77)
2. Your PR will be reviewed by the AnchorNet-Org maintainers

Good luck! Track your progress on GrantFox.

[Jagadeeshftw]

@GBOYEE good instinct on the operator-supersession adversarial test, but same as your other recent requests — you're capped at 6 open assignments right now. let's get some of the existing ones shipped before adding this to the pile.

[Jagadeeshftw]

@GBOYEE update on the cap: on review, #99/#98/#91 already had a PR referencing them (PR #102), so those freed up. i used the freed slots for your three oldest pending requests (#97, #95, #81), which puts you back at the 6-issue cap. this one (#77) will have to wait until you close out some of what's assigned. thanks for the patience.

[Jagadeeshftw]

Thanks for applying here. Please also join our Telegram group here: https://t.me/+vTbe0hOUKrFhNTJl. It helps us keep communication clear while we review contributions.

[Jagadeeshftw]

Thanks for the application — I’ve assigned this to @mordabdul1. Please also join our Telegram group here: https://t.me/+vTbe0hOUKrFhNTJl. We share queue updates there while work is in progress.