587b5b9ac2
hermes backup only walks HERMES_HOME, so memory providers that keep config/credentials in home-anchored dotdirs (honcho -> ~/.honcho, hindsight -> ~/.hindsight, openviking -> ~/.openviking) lost that data across a backup/import cycle — the peer IDs, session pairings, and API keys never made it into the archive. Add an optional MemoryProvider.backup_paths() hook (default []). The active provider declares its external paths; backup resolves them from config only (no init, no network), archives the ones under the home dir into a reserved _external/ subtree encoded relative to home, and import restores them to their original location with a home-anchored traversal guard and 0600 on credential-shaped files. Paths outside home are skipped as non-portable. honcho, hindsight, and openviking override the hook. E2E-validated full backup->import cycle plus 7 new tests.