fix(v1_public): remove unnecessary ed25519-dalek dependency

Removes ed25519-dalek from v1_public feature dependencies. The v1.public
implementation correctly uses RSA-2048 via the ring crate (non-optional
dependency), making ed25519-dalek unnecessary.

This dependency caused confusion about the cryptographic implementation
and added unnecessary compilation overhead for v1_public users.

Closes #70
Closes #53

Author: rrrodzilla

Cargo.toml

@@ -40,7 +40,7 @@ v1_local = ["v1", "local", "core", "aes", "ctr", "chacha20", "hmac", "sha2", "bl
 v2_local = ["v2", "local", "core", "blake2", "chacha20poly1305"]
 v3_local = ["v3", "local", "core", "aes", "ctr", "hmac", "sha2", "chacha20"]
 v4_local = ["v4", "local", "core", "blake2", "chacha20"]
-v1_public = ["v1", "public", "core", "ed25519-dalek"]
+v1_public = ["v1", "public", "core"]
 v2_public = ["v2", "public", "core", "ed25519-dalek", "ring/std"]
 v3_public = ["v3", "public", "core", "p384", "sha2"]
 v4_public = ["v4", "public", "core", "ed25519-dalek", "ring/std"]