refactor(inventory): move event payloads from eventbus into the domain package

[asphaltbuffet]

Strength: Worth exploring
Category: in-process, structural

Problem

Event payload structs (EntityCreatedPayload, EntityRenamedPayload, etc.) live in internal/eventbus/payloads.go — the transport layer — but are domain concepts. The producer imports the consumer's package for naming:

• internal/app/entities.go constructs eventbus.EntityCreatedPayload directly (also in RenameEntity, ReparentEntity, ChangeStatus).
• internal/app/doctor.go payloadPrototypes map references eventbus.*Payload constructors.

This creates an asymmetric dependency: app → eventbus purely to name domain shapes. The CONTEXT.md glossary already treats payloads as part of the Event vocabulary.

Solution

Move payload structs to internal/inventory/events/ (or extend inventory directly). Both app and eventbus import the domain package; neither depends on the other for payload shapes.

Files affected:

• New: internal/inventory/events/*.go (or new types in internal/inventory/)
• Update imports: internal/app/entities.go, internal/app/status.go, internal/app/doctor.go
• Update imports: internal/eventbus/handlers.go, internal/eventbus/bus.go
• Delete: internal/eventbus/payloads.go

Wins

• Locality: payload schema lives next to the EventType iota
• Leverage: doctor + bus + app share one import
• Removes app → eventbus coupling
• Composes with the event-registry refactor (refactor(eventbus): collapse event-type registration into one registry #204)
• Payloads testable without dispatch machinery
• Names match the CONTEXT.md glossary

Composes with

• refactor(eventbus): collapse event-type registration into one registry #204 — the registry is the natural call site for the relocated payload factories
• refactor(eventbus): extract PathPropagator from the three handleEntityReparented variants #207 — PathPropagator uses the relocated EntityPathChangedPayload

Source

Architecture review 2026-05-31, candidate #5 (Worth exploring).