refactor: split the library into fumi-core and make it embeddable

core/src/lib.rs

@@ -0,0 +1,22 @@
+//! `fumi-core` — the Smol Mail client library (SPEC.md 1.2).
+//!
+//! Counterpart to bunshin, the server: deriving identities from one master
+//! secret, sealing and opening mail, and talking to a mailbox over a Noise_NX
+//! TCP connection (or the Reticulum carrier behind the `rns` feature). The
+//! `fumi` crate wraps this library as a command-line client; GUI hosts embed
+//! this one directly.
+
+pub mod account;
+pub mod address;
+pub mod client;
+pub mod crypto;
+pub mod error;
+pub mod message;
+#[cfg(feature = "rns")]
+pub mod rns;
+pub mod store;
+pub mod tcp;
+pub mod transport;
+#[cfg(test)]
+mod vectors;
+