1 files changed, 37 insertions, 0 deletions
diff --git a/engine/entities/base.ts b/engine/entities/base.ts
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+++ b/engine/entities/base.ts
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+import type { GameTime } from 'time'
+import type { Brand } from 'utils'
+
+/**
+ * Branded IDs — string at runtime, distinct at compile time so a PersonId
+ * can't silently flow into a slot that expects a RelationshipId.
+ * (utils/types/brand.ts)
+ */
+export type PersonId = Brand<string, 'PersonId'>
+export type RelationshipId = Brand<string, 'RelationshipId'>
+export type PlaceId = Brand<string, 'PlaceId'>
+export type InstitutionId = Brand<string, 'InstitutionId'>
+export type WorldEventId = Brand<string, 'WorldEventId'>
+export type WorldId = Brand<string, 'WorldId'>
+export type EventLogEntryId = Brand<string, 'EventLogEntryId'>
+export type RoutineId = Brand<string, 'RoutineId'>
+export type ScheduledEventId = Brand<string, 'ScheduledEventId'>
+export type FlowEntryId = Brand<string, 'FlowEntryId'>
+export type MemoirId = Brand<string, 'MemoirId'>
+
+/** Every simulation entity wears one of these kind tags. */
+export type EntityKind = 'person' | 'relationship' | 'institution' | 'place' | 'world_event'
+
+/**
+ * The common shape every entity carries. Concrete entities extend this with
+ * their specific id/kind pair — `Person extends BaseEntity<PersonId, 'person'>`.
+ * `deterministicSeed` powers lazy Tier 3 regeneration: given the seed, the
+ * entity's trajectory is fully reproducible without persisted state.
+ * (ARCHITECTURE.md §26)
+ */
+export interface BaseEntity<Id extends string = string, K extends EntityKind = EntityKind> {
+  readonly id: Id
+  readonly kind: K
+  readonly createdAt: GameTime
+  readonly destroyedAt: GameTime | null
+  readonly deterministicSeed: number
+}