C# bindings: add procedure_http_request support + fix HTTP BSATN wire format to match spacetimedb_lib::http

crates/bindings-csharp/BSATN.Runtime/HttpWireTypes.cs

@@ -0,0 +1,77 @@
+namespace SpacetimeDB;
+
+using System.ComponentModel;
+
+// NOTE: These types define the stable BSATN wire format for the procedure_http_request ABI.
+// They must match `spacetimedb_lib::http::{Request, Response}` exactly (field order + types),
+// because the host BSATN-decodes these bytes directly and may trap on mismatch.
+// Do not reorder fields or extend these types; add a new versioned ABI instead.
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public partial record HttpMethodWire
+    : TaggedEnum<(
+        Unit Get,
+        Unit Head,
+        Unit Post,
+        Unit Put,
+        Unit Delete,
+        Unit Connect,
+        Unit Options,
+        Unit Trace,
+        Unit Patch,
+        string Extension
+    )>;
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public enum HttpVersionWire : byte
+{
+    Http09,
+    Http10,
+    Http11,
+    Http2,
+    Http3,
+}
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public partial struct HttpHeaderPairWire
+{
+    public string Name;
+    public byte[] Value;
+}
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public partial struct HttpHeadersWire
+{
+    public HttpHeaderPairWire[] Entries;
+}
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public partial struct HttpTimeoutWire
+{
+    public TimeDuration Timeout;
+}
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public partial struct HttpRequestWire
+{
+    public HttpMethodWire Method;
+    public HttpHeadersWire Headers;
+    public HttpTimeoutWire? Timeout;
+    public string Uri;
+    public HttpVersionWire Version;
+}
+
+[Type]
+[EditorBrowsable(EditorBrowsableState.Never)]
+public partial struct HttpResponseWire
+{
+    public HttpHeadersWire Headers;
+    public HttpVersionWire Version;
+    public ushort Code;
+}

crates/bindings-csharp/Runtime/Exceptions.cs

@@ -98,6 +98,11 @@ public class TransactionIsMutableException : StdbException
         "ABI call can only be made while inside a read-only transaction";
 }
 
+public class HttpException : StdbException
+{
+    public override string Message => "HTTP request failed";
+}
+
 public class UnknownException : StdbException
 {
     private readonly Errno code;