refactor: rename aris to aelis (#59)

Rename all references across the codebase: package names,
imports, source IDs, directory names, docs, and configs.

Co-authored-by: Ona <no-reply@ona.com>

packages/aelis-core/src/feed-post-processor.ts

@@ -0,0 +1,26 @@
+import type { Context } from "./context"
+import type { FeedItem } from "./feed"
+
+export interface ItemGroup {
+	/** IDs of items to present together */
+	itemIds: string[]
+	/** Summary text for the group */
+	summary: string
+}
+
+export interface FeedEnhancement {
+	/** New items to inject into the feed */
+	additionalItems?: FeedItem[]
+	/** Groups of items to present together with a summary */
+	groupedItems?: ItemGroup[]
+	/** Item IDs to remove from the feed */
+	suppress?: string[]
+	/** Map of item ID to boost score (-1 to 1). Positive promotes, negative demotes. */
+	boost?: Record<string, number>
+}
+
+/**
+ * A function that transforms feed items and produces enhancement directives.
+ * Use named functions for meaningful error attribution.
+ */
+export type FeedPostProcessor = (items: FeedItem[], context: Context) => Promise<FeedEnhancement>