refactor: deepen GSDTools query execution seams (#3085)

* refactor: deepen gsdtools query execution seams

* docs: add changeset for query seam deepening

* docs: fix changeset summary text

* fix: address coderabbit query seam findings

* test: address remaining coderabbit findings and notes

* refactor: use internal gsdtools error type import

sdk/src/query-execution-policy.ts

@@ -0,0 +1,42 @@
+import { resolveTransportPolicy } from './gsd-transport-policy.js';
+import type { GSDTransport } from './gsd-transport.js';
+import type { TransportMode } from './gsd-transport-policy.js';
+
+export interface QueryExecutionRequest {
+  legacyCommand: string;
+  legacyArgs: string[];
+  registryCommand: string;
+  registryArgs: string[];
+  mode: TransportMode;
+  projectDir: string;
+  workstream?: string;
+  preferNativeQuery: boolean;
+}
+
+/**
+ * Execution policy for query command dispatch.
+ * Owns routing decision inputs for native/subprocess dispatch.
+ */
+export class QueryExecutionPolicy {
+  constructor(private readonly transport: GSDTransport) {}
+
+  async execute(request: QueryExecutionRequest): Promise<unknown> {
+    const policy = resolveTransportPolicy(request.registryCommand);
+
+    return this.transport.run(
+      {
+        legacyCommand: request.legacyCommand,
+        legacyArgs: request.legacyArgs,
+        registryCommand: request.registryCommand,
+        registryArgs: request.registryArgs,
+        mode: request.mode,
+        projectDir: request.projectDir,
+        workstream: request.workstream,
+      },
+      {
+        preferNative: request.preferNativeQuery && policy.preferNative,
+        allowFallbackToSubprocess: policy.allowFallbackToSubprocess,
+      },
+    );
+  }
+}