Add SelfFreezoneClient wrapper for Self components

- Created SelfFreezoneClient in Self components
- Wraps SDK FreezoneScriptClient for Self-specific operations
- Implements send_verification_email method
- Uses Rhai script template for email verification
- Includes template variable substitution
- Added serde-wasm-bindgen dependency

Usage:
  let client = SelfFreezoneClient::builder()
      .supervisor_url("http://localhost:8080")
      .secret("my-secret")
      .build()?;

  client.send_verification_email(
      "user@example.com",
      "123456",
      "https://verify.com/abc"
  ).await?;

components/Cargo.toml

@@ -36,6 +36,7 @@ gloo = { workspace = true }
 gloo-timers = { workspace = true }
 serde = { workspace = true }
 serde_json = { workspace = true }
+serde-wasm-bindgen = "0.6"
 getrandom = { workspace = true }
 sha2 = { workspace = true }
 aes-gcm = { workspace = true }
@@ -43,3 +44,4 @@ base64 = { workspace = true }
 hex = { workspace = true }
 rand = { workspace = true }
 k256 = { version = "0.13", features = ["ecdsa", "sha256"] }
+pbkdf2 = { version = "0.12", features = ["hmac"], default-features = false }