feat(channel): add logo support with position and opacity settings

k-tv-backend/api/src/routes/channels/crud.rs

@@ -101,6 +101,15 @@ pub(super) async fn update_channel(
             channel.access_password_hash = Some(infra::auth::hash_password(&pw));
         }
     }
+    if let Some(logo) = payload.logo {
+        channel.logo = logo;
+    }
+    if let Some(pos) = payload.logo_position {
+        channel.logo_position = pos;
+    }
+    if let Some(opacity) = payload.logo_opacity {
+        channel.logo_opacity = opacity.clamp(0.0, 1.0);
+    }
     channel.updated_at = Utc::now();
 
     let channel = state.channel_service.update(channel).await?;