feat(mcp): update environment preferences#8728

@@ -0,0 +1,357 @@
+import { assert, expect, it } from "@effect/vitest";
+import * as NodeServices from "@effect/platform-node/NodeServices";
+import {
+  CommandId,
+  DEFAULT_SERVER_SETTINGS,
+  EnvironmentId,
+  ENVIRONMENT_MCP_MAX_WRITING_INSTRUCTIONS,
+  EnvironmentMcpPreferencesUpdateInput,
+  ProjectId,
+  ProviderInstanceId,
+  ServerSettings,
+  ThreadId,
+  type OrchestrationV2ThreadShell,
+} from "@t3tools/contracts";
+import { fromLenientJson } from "@t3tools/shared/schemaJson";
+import * as DateTime from "effect/DateTime";
+import * as Deferred from "effect/Deferred";
+import * as Effect from "effect/Effect";
+import * as Fiber from "effect/Fiber";
+import * as FileSystem from "effect/FileSystem";
+import * as Layer from "effect/Layer";
+import * as Option from "effect/Option";
+import * as Ref from "effect/Ref";
+import * as Schema from "effect/Schema";
+import * as Stream from "effect/Stream";
+
+import * as ServerSecretStore from "../auth/ServerSecretStore.ts";
+import * as ServerConfig from "../config.ts";
+import * as ServerEnvironment from "../environment/ServerEnvironment.ts";
+import {
+  type KeyedSerialExecutor,
+  makeKeyedSerialExecutor,
+  ThreadDispatchLockV2,
+  threadDispatchLockLayer,
+} from "../orchestration-v2/KeyedSerialExecutor.ts";
+import { OrchestratorV2 } from "../orchestration-v2/Orchestrator.ts";
+import { makeLayer as makeProviderAdapterRegistryLayer } from "../orchestration-v2/ProviderAdapterRegistry.ts";
+import {
+  layer as threadManagementLayer,
+  ThreadManagementService,
+} from "../orchestration-v2/ThreadManagementService.ts";
+import { makeOrchestratorV2ReplayLayerWithRegistry } from "../orchestration-v2/testkit/ProviderReplayHarness.ts";
+import { SqlitePersistenceMemory } from "../persistence/Layers/Sqlite.ts";
+import { ProviderRegistry } from "../provider/Services/ProviderRegistry.ts";
+import { makeProviderRegistryMock } from "../provider/testUtils/providerRegistryMock.ts";
+import * as ServerSettingsModule from "../serverSettings.ts";
+import {
+  EnvironmentMcpService,
+  layer as environmentMcpLayer,
+  make as makeEnvironmentMcpService,
+} from "./EnvironmentMcpService.ts";

@@ -53,3 +56,14 @@ export const makeKeyedSerialExecutor = <Key>(): Effect.Effect<KeyedSerialExecuto
         ),
     } satisfies KeyedSerialExecutor<Key>;
   });
+
+/** The single in-process admission boundary for commands targeting a V2 thread. */
+export class ThreadDispatchLockV2 extends Context.Service<
+  ThreadDispatchLockV2,
+  KeyedSerialExecutor<ThreadId>
+>()("t3/orchestration-v2/KeyedSerialExecutor/ThreadDispatchLockV2") {}
+
+export const threadDispatchLockLayer = Layer.effect(

@@ -22,3 +22,17 @@ The preference projection is a literal allowlist. It must be extended field by
 field; never spread a server settings or provider configuration object into an
 MCP result. Environment reads use cached provider state and do not call provider
 refresh or the usage service.
+
+`t3_environment_preferences_update` accepts a separate literal patch schema and
+constructs an existing `ServerSettingsPatch` field by field. The mutation runs
+under `ThreadDispatchLockV2` for the calling thread. It reloads the caller under
+that same lock, requires `full-access` plus `default`, and holds the lock through
+`ServerSettingsService.updateSettings`. Ordinary V2 policy writers use the same
+lock, so a concurrent downgrade is observed before persistence. The settings
+service remains responsible for normalization, durable storage, and existing
+cross-client notifications.
+
+The mutation exposes preset background profiles, not arbitrary timing