refactor(ts): complete legacy host removal — drop fastify/commander/zod, delete MCP SDK server, remove ManagedRuntime facades

Finishes the remaining EFFECT_NATIVE_REWRITE_PLAN stages in one verified slice:
- fastify, @fastify/websocket, commander, zod removed from all package manifests
- legacy @modelcontextprotocol/sdk stdio server deleted; effect/unstable/ai McpServer is canonical
- no ManagedRuntime or Effect.runPromise program facades remain in production source
- gateway server/rpc-contract and client rpc/socket moved onto Effect v4 native http/rpc/socket layers

Gates (force-run, no cache): check:tsgo, build, test (96 tests / 11 tasks) all green.
Native-class inventory: zero blocking production classes.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

ts/packages/base/package.json

@@ -20,14 +20,6 @@
     "test": "bunx --bun vitest run"
   },
   "dependencies": {
-    "@effect/ai-anthropic": "4.0.0-beta.78",
-    "@effect/ai-openai": "4.0.0-beta.78",
-    "@effect/ai-openrouter": "4.0.0-beta.78",
-    "@effect/atom-react": "4.0.0-beta.78",
-    "@effect/openapi-generator": "4.0.0-beta.78",
-    "@effect/opentelemetry": "4.0.0-beta.78",
-    "@effect/platform-browser": "4.0.0-beta.78",
-    "@effect/platform-bun": "4.0.0-beta.78",
     "effect": "4.0.0-beta.78",
     "nats": "^2.29.0"
   },

ts/packages/base/src/processor/async-processor.ts

@@ -7,7 +7,7 @@
  */
 
 import type { PubSubBackend } from "../backend/types.js";
-import { makeNatsBackend } from "../backend/nats.js";
+import { makeNatsBackend, makeNatsBackendScoped } from "../backend/nats.js";
 import { Cause, Config as EffectConfig, Context, Effect } from "effect";
 import { processorLifecycleError, type ProcessorLifecycleError } from "../errors.js";
 import { loadProcessorRuntimeConfig } from "../runtime/config.js";
@@ -198,6 +198,27 @@ export function makeAsyncProcessor<
   return processor;
 }
 
+export const makeAsyncProcessorScoped = Effect.fn("makeAsyncProcessorScoped")(function* <
+  RunError = ProcessorLifecycleError,
+  RunRequirements = never,
+>(
+  config: ProcessorConfig,
+  options: AsyncProcessorRuntimeOptions<RunError, RunRequirements> = {},
+) {
+  if (config.pubsub !== undefined) {
+    return makeAsyncProcessor(config, options);
+  }
+
+  const pubsub = yield* makeNatsBackendScoped(config.pubsubUrl ?? "nats://localhost:4222");
+  return makeAsyncProcessor(
+    {
+      ...config,
+      pubsub,
+    },
+    options,
+  );
+});
+
 export type AsyncProcessor<
   RunError = ProcessorLifecycleError,
   RunRequirements = never,

ts/packages/base/src/processor/index.ts

@@ -1,6 +1,7 @@
 export {
   AsyncProcessor,
   makeAsyncProcessor,
+  makeAsyncProcessorScoped,
   type ConfigHandler,
   type EffectConfigHandler,
   type AsyncProcessorRuntime,

ts/packages/base/src/processor/program.ts

@@ -11,7 +11,7 @@ import {
   type ProcessorLifecycleError,
   type PubSubError,
 } from "../errors.js";
-import { makeNatsBackend } from "../backend/nats.js";
+import { makeNatsBackendScoped } from "../backend/nats.js";
 import { makePubSubService, PubSub } from "../backend/pubsub.js";
 import {
   ConsumerFactory,
@@ -119,18 +119,9 @@ export function makeProcessorProgram<
         manageProcessSignals: false,
       } as Config;
 
-      const pubsub = makePubSubService(makeNatsBackend(runtimeConfig.pubsubUrl ?? "nats://localhost:4222"));
+      const backend = yield* makeNatsBackendScoped(runtimeConfig.pubsubUrl ?? "nats://localhost:4222");
+      const pubsub = makePubSubService(backend);
       const messagingConfig = yield* loadMessagingRuntimeConfig();
-      yield* Effect.addFinalizer(() =>
-        pubsub.close.pipe(
-          Effect.catch((error) =>
-            Effect.logError("[PubSub] Failed to close processor backend", {
-              error: error.message,
-              operation: error.operation,
-            }),
-          ),
-        ),
-      );
       const processorEffect = runProcessorScoped<Config, RunError, RunRequirements>(
         runtimeConfig,
         options.make,
@@ -202,18 +193,9 @@ export function makeFlowProcessorProgram<
         manageProcessSignals: false,
       } as Config;
 
-      const pubsub = makePubSubService(makeNatsBackend(runtimeConfig.pubsubUrl ?? "nats://localhost:4222"));
+      const backend = yield* makeNatsBackendScoped(runtimeConfig.pubsubUrl ?? "nats://localhost:4222");
+      const pubsub = makePubSubService(backend);
       const messagingConfig = yield* loadMessagingRuntimeConfig();
-      yield* Effect.addFinalizer(() =>
-        pubsub.close.pipe(
-          Effect.catch((error) =>
-            Effect.logError("[PubSub] Failed to close processor backend", {
-              error: error.message,
-              operation: error.operation,
-            }),
-          ),
-        ),
-      );
 
       const configHandlers = options.configHandlers?.(runtimeConfig);
       const processorOptions = {