feature: Phase 18.6 Track A — public Settings menu + streaming-quality toggle

DeepDrftPublic/Services/SettingsService.cs

@@ -0,0 +1,25 @@
+using DeepDrftPublic.Client.Common;
+using DeepDrftPublic.Client.Services;
+
+namespace DeepDrftPublic.Services;
+
+/// <summary>
+/// Server-side prerender reader for public-site listener settings (Phase 18 wave 18.6), the sibling of
+/// <see cref="DarkModeService"/>. Reads each preference's cookie via <see cref="IHttpContextAccessor"/>
+/// during prerender and seeds the scoped <see cref="PublicSiteSettings"/>, which <c>MainLayout</c> then
+/// rounds through <c>PersistentComponentState</c> into WASM — so the first paint already reflects the
+/// listener's choice with no wrong-default flash (the streaming-quality analogue of the wrong-theme fix).
+/// Inherits the shared cookie names + parsers from <see cref="SettingsServiceBase"/> so the server read and
+/// the client write agree on one wire format.
+/// </summary>
+public class SettingsService(PublicSiteSettings settings, IHttpContextAccessor httpAccessor) : SettingsServiceBase
+{
+    public void CheckSettings()
+    {
+        var cookies = httpAccessor.HttpContext?.Request.Cookies;
+        if (cookies is null) return;
+
+        cookies.TryGetValue(StreamQualityCookieName, out var streamQuality);
+        settings.StreamQuality = ParseStreamQuality(streamQuality);
+    }
+}