refactor: code smell fixes — tests, events, naming

- Tests for ExecutePipelineHandler (happy path, fallback, disabled skip, failure retry, not found)
- Tests for ProcessNextJobHandler (empty queue, process, drain multiple)
- DerivativeGenerated domain event + event-payload mapping + event_store aggregate
- Renamed event-payload → adapters-event-payload, event-transport → adapters-event-transport

crates/adapters/postgres/Cargo.toml

@@ -5,7 +5,7 @@ edition = "2024"
 
 [dependencies]
 domain        = { workspace = true }
-event-payload = { workspace = true }
+adapters-event-payload = { workspace = true }
 sqlx          = { workspace = true, features = ["postgres", "runtime-tokio", "migrate", "uuid", "chrono", "json"] }
 uuid          = { workspace = true }
 chrono        = { workspace = true }

crates/adapters/postgres/src/event_store.rs

@@ -1,9 +1,9 @@
 use crate::helpers::{MapDomainError, pg_repo};
+use adapters_event_payload::EventPayload;
 use async_trait::async_trait;
 use domain::{
     errors::DomainError, events::DomainEvent, ports::EventStore, value_objects::SystemId,
 };
-use event_payload::EventPayload;
 use uuid::Uuid;
 
 pg_repo!(PostgresEventStore);
@@ -14,7 +14,8 @@ fn aggregate_id(event: &DomainEvent) -> Uuid {
         DomainEvent::AssetIngested { asset_id, .. }
         | DomainEvent::MetadataUpdated { asset_id, .. }
         | DomainEvent::AssetDeleted { asset_id, .. }
-        | DomainEvent::SidecarSyncRequested { asset_id, .. } => *asset_id.as_uuid(),
+        | DomainEvent::SidecarSyncRequested { asset_id, .. }
+        | DomainEvent::DerivativeGenerated { asset_id, .. } => *asset_id.as_uuid(),
 
         DomainEvent::ShareCreated { scope_id, .. } | DomainEvent::ShareRevoked { scope_id, .. } => {
             *scope_id.as_uuid()