Archive the whole data volume in Backups, not just the database

Settings > Backups gains a whole-data archive beside the database
snapshots, and both lists now fully work from the page.

- Data archives: `write-data-backup-archive.ts` tars all of DATA_DIR into
  BACKUP_ARCHIVE_DIR as cobble-data-<epoch-ms>.tar.gz, every entry under one
  root folder named after the archive, writing a .part name and renaming on
  success so a cut-off run is never listed. The newest
  AppData.DataBackupsKept are kept; db/.backups is left as it is.
- Restore: `restore-data-backup.ts` extracts to a temp dir, requires one
  root folder holding a db folder, takes a safety archive first, then
  replaces DATA_DIR (the database snapshots included) and `restart-app.ts`
  restarts the process through the docker socket, since the open SQLite
  handle points at the replaced file.
- Upload and restore: a modal over each list (database file or data
  archive), replacing the old /admin/settings/backups/restore page.
- Delete for both kinds, icon-only row actions shared through
  RowIconButton, and restore on every row.
- One backup or restore of either kind at a time (with-backup-run-lock).
- BACKUP_ARCHIVE_DIR is a start-up path (ProcessOnlyEnvKeys); the installer
  mounts $COBBLE_HOME/backups-archives at /backups-archives and recreates a
  container that lacks it. The image installs tar and gzip.

src/functions/backend/backups/resolve-data-backup-path.ts

@@ -0,0 +1,22 @@
+import path from "path";
+import grabBackupArchiveDir from "@/src/utils/grab-backup-archive-dir";
+import grabDataBackups from "./grab-data-backups";
+
+type Params = {
+    backup_name?: string;
+};
+
+/**
+ * Resolves a data archive name from the request to its absolute path.
+ * Only names of existing archives are accepted, so arbitrary paths can't
+ * be read or written.
+ */
+export default function resolveDataBackupPath({ backup_name }: Params) {
+    const backup = grabDataBackups().find((b) => b.name === backup_name);
+
+    if (!backup) {
+        throw new Error(`Archive not found`);
+    }
+
+    return path.join(grabBackupArchiveDir(), backup.name);
+}