Fix double disposal in shutdown test and remove unused drain from CoalescingDrainableWorker

- Make dispose() in Manager.test.ts idempotent with a disposed guard so
  the afterEach cleanup does not double-close the scope/runtime.
- Remove the unused drain property from CoalescingDrainableWorker interface
  and implementation since no consumer of this worker type uses it.

Author: cursoragent

apps/server/src/terminal/Layers/Manager.test.ts

@@ -211,6 +211,7 @@ async function makeManager(
     ).pipe(Effect.forkIn(eventScope)),
   );
 
+  let disposed = false;
   return {
     baseDir,
     logsDir,
@@ -221,6 +222,8 @@ async function makeManager(
     run: <A, E>(effect: Effect.Effect<A, E>) => runtime.runPromise(effect),
     getEvents: () => Effect.runPromise(Ref.get(eventsRef)),
     dispose: async () => {
+      if (disposed) return;
+      disposed = true;
       await Effect.runPromise(Scope.close(eventScope, Exit.void));
       await runtime.dispose();
     },

packages/shared/src/CoalescingDrainableWorker.ts

@@ -13,7 +13,6 @@ import { Effect, TxQueue, TxRef } from "effect";
 export interface CoalescingDrainableWorker<K, V> {
   readonly enqueue: (key: K, value: V) => Effect.Effect<void>;
   readonly drainKey: (key: K) => Effect.Effect<void>;
-  readonly drain: Effect.Effect<void>;
 }
 
 interface CoalescingWorkerState<K, V> {
@@ -126,16 +125,6 @@ export const makeCoalescingDrainableWorker = <K, V, E, R>(options: {
         Effect.asVoid,
       );
 
-    const drain: CoalescingDrainableWorker<K, V>["drain"] = TxRef.get(stateRef).pipe(
-      Effect.tap((state) =>
-        state.latestByKey.size > 0 || state.queuedKeys.size > 0 || state.activeKeys.size > 0
-          ? Effect.txRetry
-          : Effect.void,
-      ),
-      Effect.asVoid,
-      Effect.tx,
-    );
-
     const drainKey: CoalescingDrainableWorker<K, V>["drainKey"] = (key) =>
       TxRef.get(stateRef).pipe(
         Effect.tap((state) =>
@@ -147,5 +136,5 @@ export const makeCoalescingDrainableWorker = <K, V, E, R>(options: {
         Effect.tx,
       );
 
-    return { enqueue, drainKey, drain } satisfies CoalescingDrainableWorker<K, V>;
+    return { enqueue, drainKey } satisfies CoalescingDrainableWorker<K, V>;
   });