Fix review findings: document implements clause behavior, remove unused imports

- Add explanatory comment on getComposition/iface.name in object-type.tsx
  clarifying that pre-mutation names match post-mutation names (mutation
  engine doesn't rename models)
- Remove unused `type Model` import from all G2 test files

Author: FionaBronwen

packages/graphql/src/components/types/object-type.tsx

@@ -25,7 +25,10 @@ export function ObjectType(props: ObjectTypeProps) {
   const implementations = getComposition(program, props.type);
   const operationFields = getOperationFields(program, props.type);
 
-  // Convert interface implementations to string references
+  // Convert interface implementations to string references.
+  // Note: getComposition returns original (pre-mutation) models from decorator state.
+  // This works because the mutation engine doesn't rename models, so iface.name
+  // matches the name used by InterfaceType for the same model.
   const implementsRefs = implementations?.map((iface) => iface.name) || [];
 
   return (

packages/graphql/test/components/input-type.test.tsx

@@ -1,4 +1,3 @@
-import { type Model } from "@typespec/compiler";
 import { t } from "@typespec/compiler/testing";
 import { describe, expect, it, beforeEach } from "vitest";
 import { InputType } from "../../src/components/types/index.js";

packages/graphql/test/components/interface-type.test.tsx

@@ -1,4 +1,3 @@
-import { type Model } from "@typespec/compiler";
 import { t } from "@typespec/compiler/testing";
 import { describe, expect, it, beforeEach } from "vitest";
 import { InterfaceType } from "../../src/components/types/index.js";

packages/graphql/test/components/object-type.test.tsx

@@ -1,4 +1,3 @@
-import { type Model } from "@typespec/compiler";
 import { t } from "@typespec/compiler/testing";
 import * as gql from "@alloy-js/graphql";
 import { describe, expect, it, beforeEach } from "vitest";