fix(inbound-api): endpoint filter hot-reads MaxRequestBodyBytes via IOptionsMonitor

Claude-Session: https://claude.ai/code/session_01MtdgwpEeCUn6cUA5f1LMPj

src/ZB.MOM.WW.ScadaBridge.InboundAPI/InboundApiEndpointFilter.cs

@@ -24,17 +24,17 @@ namespace ZB.MOM.WW.ScadaBridge.InboundAPI;
 public sealed class InboundApiEndpointFilter : IEndpointFilter
 {
     private readonly ILogger<InboundApiEndpointFilter> _logger;
-    private readonly InboundApiOptions _options;
+    private readonly IOptionsMonitor<InboundApiOptions> _options;
 
     /// <summary>Initializes a new <see cref="InboundApiEndpointFilter"/> with the given logger and options.</summary>
     /// <param name="logger">Logger for request rejection diagnostics.</param>
-    /// <param name="options">Inbound API options including the maximum request body size.</param>
+    /// <param name="options">Live-reloadable inbound API options, read per-request.</param>
     public InboundApiEndpointFilter(
         ILogger<InboundApiEndpointFilter> logger,
-        IOptions<InboundApiOptions> options)
+        IOptionsMonitor<InboundApiOptions> options)
     {
         _logger = logger;
-        _options = options.Value;
+        _options = options;
     }
 
     /// <summary>Applies active-node gating and request body size checks before delegating to the next filter or handler.</summary>
@@ -63,7 +63,7 @@ public sealed class InboundApiEndpointFilter : IEndpointFilter
         // Cap the request body size. Reject an over-limit body up
         // front via Content-Length; also lower the per-request max body size so a
         // chunked/unknown-length stream is cut off by Kestrel as it is read.
-        var maxBytes = _options.MaxRequestBodyBytes;
+        var maxBytes = _options.CurrentValue.MaxRequestBodyBytes;
         if (httpContext.Request.ContentLength is { } declaredLength && declaredLength > maxBytes)
         {
             _logger.LogWarning(