feat: emit NominationRevoked when revokeDelegate clears a pending nomination

[chasingrainbows]

Description

revokeDelegate() silently dropped a pending (not-yet-effective) nomination without emitting an event, while revokeNomination() emits NominationRevoked for the same reset. This PR makes the event stream consistent: revokeDelegate() now calls _settle() and emits NominationRevoked(pending) when an unmatured pending nomination is dropped, before the existing DelegateRevoked.

A matured pending nomination is folded into the current delegate by _settle() and is reported via DelegateRevoked only — no duplicate event. External state after the call is unchanged; only the event stream differs. terminate() is intentionally left untouched (end of contract life).

Related Issue/Task

• Related task: N/A
• Epic: N/A

How Has This Been Tested?

• Local tests
• Manual testing (describe steps)
• Not tested (explain why)

forge test: 82/82 passing, including fuzz and invariant suites. Coverage stays at 100% (lines/branches/functions). Three new tests:

• test_revokeDelegate_emitsNominationRevokedForPending — event order NominationRevoked → DelegateRevoked for an unmatured pending nomination
• test_revokeDelegate_noNominationRevokedWhenNoPending — via vm.recordLogs(), proves only DelegateRevoked is emitted
• test_revokeDelegate_noNominationRevokedWhenPendingMatured — matured pending goes into DelegateRevoked only

Checklist

• Documentation updated (if required)
• New tests added (if applicable)

[Copilot]

Pull request overview

This PR makes revokeDelegate()’s event stream consistent with revokeNomination() by emitting NominationRevoked when revokeDelegate() clears a not-yet-effective pending nomination, while preserving the existing external state outcomes.

Changes:

• Update revokeDelegate() to _settle() first, then emit NominationRevoked(pending) only when an unmatured pending nomination is actually dropped, followed by DelegateRevoked.
• Document the new emission behavior for revokeDelegate() in IDelegationContract.
• Add unit tests that assert the new event ordering/absence rules across pending/no-pending/matured-pending scenarios (using vm.recordLogs() where appropriate).

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated no comments.

File	Description
src/DelegationContract.sol	Calls _settle(), conditionally emits NominationRevoked for non-matured pending, then revokes the effective delegate and emits DelegateRevoked.
src/interfaces/IDelegationContract.sol	Updates NatSpec for revokeDelegate() to describe the additional NominationRevoked emission when dropping a not-yet-effective nomination.
test/unit/DelegationContract.t.sol	Adds tests covering (1) pending dropped emits NominationRevoked then DelegateRevoked, (2) no pending emits only DelegateRevoked, (3) matured pending results in only DelegateRevoked for the matured delegate.

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