feat(backend): policy rules show what they inherit, files of a chat or folder go to trash in one batch, trash list is paged

backend/src/utils/read/chats.py

@@ -176,6 +176,18 @@ async def list_chats(
     return [_chat_item(row) for row in rows]
 
 
+async def folder_chat_ids(
+    pool: asyncpg.Pool, account_id: int, folder: FolderSpec
+) -> list[int]:
+    rows_sql = _CHAT_ROWS.format(ids=_ALL_IDS)
+    rows = await pool.fetch(
+        f"SELECT chat.chat_id FROM ({rows_sql}) chat WHERE {_folder_filter(1)}",  # noqa: S608
+        account_id,
+        *_folder_params(folder),
+    )
+    return [row["chat_id"] for row in rows]
+
+
 async def get_chat(
     pool: asyncpg.Pool, account_id: int, chat_id: int
 ) -> ChatListItem | None: