2.2 FramesOptions (frames.json binding + validator)

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/FrameProcessor/Program.cs

@@ -1,7 +1,10 @@
 using FrameProcessor.Configuration;
+using Microsoft.Extensions.Options;
 
 var builder = WebApplication.CreateBuilder(args);
 
+builder.Configuration.AddJsonFile("frames.json", optional: false, reloadOnChange: true);
+
 builder.Services.AddControllers();
 
 builder.Services.AddOptions<MqttOptions>()
@@ -24,6 +27,11 @@ builder.Services.AddOptions<ApiKeyOptions>()
     .ValidateDataAnnotations()
     .ValidateOnStart();
 
+builder.Services.AddSingleton<IValidateOptions<FramesOptions>, FramesOptionsValidator>();
+builder.Services.AddOptions<FramesOptions>()
+    .Bind(builder.Configuration)
+    .ValidateOnStart();
+
 var app = builder.Build();
 
 app.MapControllers();