fix(contract): add event_version to protocol_fee_set event topic #853

[Nwapu-TrustJah]

Overview

Fixes the set_protocol_fee event to include event_version(&env) in its topic tuple, consistent with every other admin-config event in the codebase. The protocol_fee_set event was the only event missing the version marker, which broke indexer filtering using versioned event selectors like ("protocol_fee_set", 1).

Related Issue

Fixes #853

Changes

• [MODIFY] contracts/predinex/src/lib.rs — add event_version(&env) to the protocol_fee_set event topic tuple

// Before:
env.events()
    .publish((Symbol::new(&env, "protocol_fee_set"),), (caller, old_fee_bps, fee_bps));

// After:
env.events().publish(
    (Symbol::new(&env, "protocol_fee_set"), event_version(&env)),
    (caller, old_fee_bps, fee_bps),
);

Verification Results

cargo test --workspace protocol_fee
✅ protocol_fee_set event now includes event_version in topic tuple
✅ Indexer filter ("protocol_fee_set", 1) correctly captures this event
✅ All existing event tests pass

Acceptance Criteria

Criteria	Status
protocol_fee_set event topic tuple contains exactly two elements	✅ symbol + version
Version-1 event filter captures this event alongside other config events	✅ consistent with other events
Indexer/parser handles updated topic correctly	✅ versioned topic included