Actually verify user credentials

rc_core/Cargo.toml

@@ -11,4 +11,9 @@ serde.workspace = true
 serde_json.workspace = true
 chrono = "0.4"
 polariton_server.workspace = true
-tokio = { version = "1.43", features = [ "net", "macros", "rt-multi-thread", "io-util", "time"] }
+tokio = { version = "1.43", features = [ "net", "macros", "rt-multi-thread", "io-util", "time" ] }
+
+# auth
+libfj.workspace = true
+jsonwebtoken = "9"
+argon2 = { version = "0.5", features = [ "std" ] }