#[derive(Debug, Clone, PartialEq, Eq)]
pub enum BackendType {
    Redb,
    Sled,
    Tantivy, // Full-text search backend (no KV storage)
}

#[derive(Debug, Clone)]
pub struct DBOption {
    pub dir: String,
    pub port: u16,
    pub debug: bool,
    // Deprecated for data DBs; retained for backward-compat on CLI parsing
    pub encrypt: bool,
    // Deprecated for data DBs; retained for backward-compat on CLI parsing
    pub encryption_key: Option<String>,
    pub backend: BackendType,
    // New: required admin secret, used to encrypt DB 0 and authorize admin operations
    pub admin_secret: String,
}