test(perf): avoid spawn workspace plugin metadata scans

src/agents/pi-embedded-runner/run/attempt.spawn-workspace.test-support.ts

@@ -14,6 +14,7 @@ import type {
   IngestResult,
 } from "../../../context-engine/types.js";
 import { formatErrorMessage } from "../../../infra/errors.js";
+import type { PluginMetadataSnapshot } from "../../../plugins/plugin-metadata-snapshot.js";
 import {
   normalizeLowercaseStringOrEmpty,
   normalizeOptionalLowercaseString,
@@ -229,6 +230,51 @@ export function getHoisted(): AttemptSpawnWorkspaceHoisted {
   return hoisted;
 }
 
+const emptyPluginMetadataSnapshot: PluginMetadataSnapshot = {
+  policyHash: "",
+  index: {
+    version: 1,
+    hostContractVersion: "test",
+    compatRegistryVersion: "test",
+    migrationVersion: 1,
+    policyHash: "",
+    generatedAtMs: 1,
+    installRecords: {},
+    plugins: [],
+    diagnostics: [],
+  },
+  registryDiagnostics: [],
+  manifestRegistry: { plugins: [], diagnostics: [] },
+  plugins: [],
+  diagnostics: [],
+  byPluginId: new Map(),
+  normalizePluginId: (pluginId: string) => pluginId,
+  owners: {
+    channels: new Map(),
+    channelConfigs: new Map(),
+    providers: new Map(),
+    modelCatalogProviders: new Map(),
+    cliBackends: new Map(),
+    setupProviders: new Map(),
+    commandAliases: new Map(),
+    contracts: new Map(),
+  },
+  metrics: {
+    registrySnapshotMs: 0,
+    manifestRegistryMs: 0,
+    ownerMapsMs: 0,
+    totalMs: 0,
+    indexPluginCount: 0,
+    manifestPluginCount: 0,
+  },
+};
+
+vi.mock("../../../plugins/plugin-metadata-snapshot.js", () => ({
+  isPluginMetadataSnapshotCompatible: () => true,
+  listPluginOriginsFromMetadataSnapshot: () => new Map(),
+  loadPluginMetadataSnapshot: () => emptyPluginMetadataSnapshot,
+}));
+
 vi.mock("@mariozechner/pi-coding-agent", () => {
   function AuthStorage() {}
   class DefaultResourceLoader {