[style](trx-client, trx-frontend-http): fix clippy warnings

- Derive Default for SameSite enum in auth.rs using #[default] attribute
- Derive Default for CookieSameSite enum in config.rs
- Replace and_then(|x| Some(y)) with map(|x| y) in extract_session_id()

All clippy warnings resolved. Tests pass.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
Signed-off-by: Stanislaw Grams <stanislawgrams@gmail.com>

src/trx-client/trx-frontend/trx-frontend-http/src/auth.rs

@@ -132,9 +132,10 @@ impl Default for SessionStore {
 }
 
 /// Cookie SameSite attribute
-#[derive(Debug, Clone, Copy, PartialEq, Eq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq, Default)]
 pub enum SameSite {
     Strict,
+    #[default]
     Lax,
     None,
 }
@@ -149,12 +150,6 @@ impl SameSite {
     }
 }
 
-impl Default for SameSite {
-    fn default() -> Self {
-        Self::Lax
-    }
-}
-
 /// Runtime authentication configuration
 #[derive(Debug, Clone)]
 pub struct AuthConfig {
@@ -260,7 +255,7 @@ pub struct LoginResponse {
 /// Extract session from cookie
 fn extract_session_id(req: &HttpRequest) -> Option<SessionId> {
     req.cookie("trx_http_sid")
-        .and_then(|cookie| Some(cookie.value().to_string()))
+        .map(|cookie| cookie.value().to_string())
 }
 
 /// Get session from request, return role if valid