What to save
• The database (PostgreSQL here). Workflows, credentials and execution history live in it. The dump is kept only after it has been read back in full with pg_restore -f /dev/null. pg_restore --list only reads the table of contents.
• The encryption key. n8n generates it on first launch and stores it in the ~/.n8n folder, unless you set N8N_ENCRYPTION_KEY. Credentials are encrypted with it. Restore the database with another key and you get "Credentials could not be decrypted", and only the original key fixes it. Put the key in a password manager on day one.
• The ~/.n8n data folder, as a tarball next to the dump.