Replace Argon2 with salted SHA-256 password hashes

Cargo.toml

@@ -7,10 +7,10 @@ description = "A minimal HTTP forward proxy with OpenTelemetry observability"
 license = "Apache-2.0"
 
 [dependencies]
-argon2 = { version = "0.6", features = ["zeroize"] }
 base64 = "0.23"
 bytes = "1.11"
 clap = { version = "4.6", features = ["derive"] }
+getrandom = "0.4"
 http = "1.4"
 http-body-util = "0.1.5"
 hyper = { version = "1.12", features = ["client", "http1", "server"] }
@@ -23,6 +23,8 @@ ipnet = "2.12"
 rpassword = "7.5"
 serde = { version = "1", features = ["derive"] }
 serde_norway = "0.9"
+sha2 = "0.11"
+subtle = "2.6"
 thiserror = "2"
 tokio = { version = "1", features = ["io-util", "macros", "net", "rt-multi-thread", "signal", "sync", "time"] }
 tracing = "0.1"