Add additive KDBX importer

crates/storage/Cargo.toml

@@ -18,6 +18,7 @@ gix-config.workspace = true
 hmac.workspace = true
 image.workspace = true
 keyring-core.workspace = true
+keepass.workspace = true
 pgp.workspace = true
 qrcode.workspace = true
 rand.workspace = true
@@ -49,6 +50,7 @@ arboard.workspace = true
 
 [dev-dependencies]
 hex = "0.4"
+keepass = { workspace = true, features = ["save_kdbx4"] }
 nix = { version = "0.31", features = ["fs"] }
 rand_chacha = "0.3"
 smallvec = "1.15"