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/context-provider.ts

@@ -0,0 +1,35 @@
+/**
+ * Provides context values reactively and on-demand.
+ *
+ * Implementations push updates when values change (reactive) and
+ * return current values when requested (for manual refresh).
+ *
+ * @example
+ * ```ts
+ * class LocationProvider implements ContextProvider<Location> {
+ *   readonly key = LocationKey
+ *
+ *   onUpdate(callback: (value: Location) => void): () => void {
+ *     const watchId = navigator.geolocation.watchPosition(pos => {
+ *       callback({ lat: pos.coords.latitude, lng: pos.coords.longitude, accuracy: pos.coords.accuracy })
+ *     })
+ *     return () => navigator.geolocation.clearWatch(watchId)
+ *   }
+ *
+ *   async fetchCurrentValue(): Promise<Location> {
+ *     const pos = await getCurrentPosition()
+ *     return { lat: pos.coords.latitude, lng: pos.coords.longitude, accuracy: pos.coords.accuracy }
+ *   }
+ * }
+ * ```
+ */
+export interface ContextProvider<T = unknown> {
+	/** The context key this provider populates */
+	readonly key: string
+
+	/** Subscribe to value changes. Returns cleanup function. */
+	onUpdate(callback: (value: T) => void): () => void
+
+	/** Fetch current value on-demand (used for manual refresh). */
+	fetchCurrentValue(): Promise<T>
+}