fix(csharp-conformance): read expect-error via hyphenated convention (corpus parity)

A parallel change pinned the C# query-DSL key to camelCase
(`[YamlMember(Alias = "expectError")]`), but the corpus authors it hyphenated
(`expect-error:`, matching `seed-data:`) and TS reads `expect-error` — so C#
read null and the tph-no-cross-subtype-update expectations were silently
dropped. Drop the stale alias; HyphenatedNamingConvention maps ExpectError →
expect-error automatically, consistent with every other field + the TS parser.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

Author: dmealing

server/csharp/MetaObjects.IntegrationTests/Runner/ScenarioLoader.cs

@@ -131,10 +131,9 @@ private sealed class QuerySpecYaml
         // Same rationale as Insert — UPDATE re-encode of every subtype is the point of
         // update-delete-all-types.yaml, so it must use the same coercion as roundtrip.
         public YamlNode? Data { get; set; }
-        // The corpus authors this key in camelCase (`expectError:`) while most other
-        // keys are hyphenated (`seed-data:`); the hyphenated naming convention would
-        // map it to `expect-error`, so pin the literal camelCase alias the fixtures use.
-        [YamlMember(Alias = "expectError", ApplyNamingConventions = false)]
+        // The corpus authors this key hyphenated (`expect-error:`, matching
+        // `seed-data:`); the HyphenatedNamingConvention maps ExpectError → expect-error
+        // automatically, so no explicit alias is needed (TS reads q["expect-error"]).
         public bool? ExpectError { get; set; }
         // For op: roundtrip — the field-keyed row to WRITE through the EF runtime.
         // Captured as a raw YamlNode (scalar style preserved) so the writer can honor