perf(api,frontend): index hot queries, paginate chats, fix realtime

frontend/src/lib/components/policy/PolicyEditor.svelte

@@ -16,6 +16,7 @@
   import Icon from "$lib/components/ui/Icon.svelte";
   import Spinner from "$lib/components/ui/Spinner.svelte";
   import { accounts } from "$lib/stores/accounts.svelte";
+  import { createChatPicker } from "$lib/stores/chat-picker.svelte";
   import { chats } from "$lib/stores/chats.svelte";
   import { toasts } from "$lib/stores/toasts.svelte";
 
@@ -79,15 +80,25 @@
       (f) => !folderPolicies.some((p) => p.scope_id === f.folder_id)
     )
   );
+  const picker = createChatPicker();
   const availableChats = $derived(
-    chats.list
-      .filter((c) => !chatPolicies.some((p) => p.scope_id === c.chat_id))
-      .filter((c) =>
-        (c.title ?? "").toLowerCase().includes(chatFilter.trim().toLowerCase())
-      )
-      .slice(0, 40)
+    picker.results.filter(
+      (c) => !chatPolicies.some((p) => p.scope_id === c.chat_id)
+    )
   );
 
+  $effect(() => {
+    picker.search(chatFilter);
+  });
+
+  $effect(() => {
+    for (const policy of chatPolicies) {
+      if (policy.scope_id !== null) {
+        chats.ensure(policy.scope_id);
+      }
+    }
+  });
+
   function folderTitle(id: number | null): string {
     return folders.find((f) => f.folder_id === id)?.title ?? `Папка ${id}`;
   }