(feat): add cache package

(feat): improve local storage security
(feat): move settings to dedicated settings package

packages/cache/src/helpers.ts

@@ -0,0 +1,30 @@
+import type { CachedMessage, ConversationWindow } from "./schemas";
+
+export function trimMessages(
+  messages: readonly CachedMessage[],
+  limit: number,
+): CachedMessage[] {
+  return [...messages]
+    .sort((a, b) => b.SendTime - a.SendTime)
+    .slice(0, limit)
+    .sort((a, b) => a.SendTime - b.SendTime);
+}
+
+export function replaceConversation(
+  windows: readonly ConversationWindow[],
+  replacement: ConversationWindow,
+): ConversationWindow[] {
+  return [
+    replacement,
+    ...windows.filter((item) => item.UserId !== replacement.UserId),
+  ];
+}
+
+export function selectConversationWindows(
+  windows: readonly ConversationWindow[],
+  limit: number,
+): ConversationWindow[] {
+  return [...windows]
+    .sort((a, b) => b.LastMessageAt - a.LastMessageAt || a.UserId - b.UserId)
+    .slice(0, limit);
+}