fix: mark MQTT int accessors that hide large and schema values as obsolete

MQTTServerBinding.SessionExpiryInterval, MaximumPacketSize and
MQTTOperationBinding.MessageExpiryInterval are int? views over the
MQTTIntegerOrSchema values. They return null when the value is a schema
or above Int32.MaxValue, which MQTT allows (up to 4294967295; for the
session expiry interval 0xFFFFFFFF means "never expires"). Callers
cannot tell that apart from "not set".

Keep the properties for compatibility, but document the behaviour and
mark them [Obsolete] pointing to the *Value properties. Tests now use
the *Value properties.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

Author: bielu

src/ByteBard.AsyncAPI.Bindings/MQTT/MQTTOperationBinding.cs

@@ -35,6 +35,11 @@ public bool Retain
         /// <summary>
         /// Interval in seconds or a Schema Object containing the definition of the lifetime of the message.
         /// </summary>
+        /// <remarks>
+        /// Returns null when the value is a schema or does not fit in an Int32 (MQTT allows up to 4294967295).
+        /// Use <see cref="MessageExpiryIntervalValue"/> to read every value.
+        /// </remarks>
+        [Obsolete("Returns null for schema values and values above Int32.MaxValue. Use MessageExpiryIntervalValue instead.")]
         public int? MessageExpiryInterval
         {
             get => this.MessageExpiryIntervalValue?.Integer;

src/ByteBard.AsyncAPI.Bindings/MQTT/MQTTServerBinding.cs

@@ -37,6 +37,11 @@ public class MQTTServerBinding : ServerBinding<MQTTServerBinding>
         /// Interval in seconds the broker maintains a session
         /// for a disconnected client until this interval expires.
         /// </summary>
+        /// <remarks>
+        /// Returns null when the value is a schema or does not fit in an Int32 (MQTT allows up to 4294967295).
+        /// Use <see cref="SessionExpiryIntervalValue"/> to read every value.
+        /// </remarks>
+        [Obsolete("Returns null for schema values and values above Int32.MaxValue. Use SessionExpiryIntervalValue instead.")]
         public int? SessionExpiryInterval
         {
             get => this.SessionExpiryIntervalValue?.Integer;
@@ -50,6 +55,11 @@ public int? SessionExpiryInterval
         /// Number of bytes representing the maximum packet size
         /// the client is willing to accept.
         /// </summary>
+        /// <remarks>
+        /// Returns null when the value is a schema or does not fit in an Int32 (MQTT allows up to 4294967295).
+        /// Use <see cref="MaximumPacketSizeValue"/> to read every value.
+        /// </remarks>
+        [Obsolete("Returns null for schema values and values above Int32.MaxValue. Use MaximumPacketSizeValue instead.")]
         public int? MaximumPacketSize
         {
             get => this.MaximumPacketSizeValue?.Integer;

test/ByteBard.AsyncAPI.Tests/Bindings/BindingExtensions_Should.cs

@@ -55,7 +55,7 @@ public void V2_TryGetValue_WithOperationBinding_ReturnsBinding()
             operation.Bindings.Add(new MQTTOperationBinding
             {
                 QoS = 23,
-                MessageExpiryInterval = 1,
+                MessageExpiryIntervalValue = MQTTIntegerOrSchema.FromInteger(1),
                 Retain = true,
             });
 

test/ByteBard.AsyncAPI.Tests/MQTT/MQTTBindings_Should.cs

@@ -46,8 +46,8 @@ public void V2_MQTTServerBinding_FilledObject_SerializesAndDeserializes()
                     Retain = false,
                 },
                 KeepAlive = 60,
-                SessionExpiryInterval = 600,
-                MaximumPacketSize = 1200,
+                SessionExpiryIntervalValue = MQTTIntegerOrSchema.FromInteger(600),
+                MaximumPacketSizeValue = MQTTIntegerOrSchema.FromInteger(1200),
             });
 
             // Act
@@ -82,7 +82,7 @@ public void V2_MQTTOperationBinding_WithFilledObject_SerializesAndDeserializes()
             {
                 QoS = 2,
                 Retain = true,
-                MessageExpiryInterval = 60,
+                MessageExpiryIntervalValue = MQTTIntegerOrSchema.FromInteger(60),
             });
 
             // Act