feat: add experimental background subagents (#27084)

packages/opencode/test/session/prompt.test.ts

@@ -6,6 +6,7 @@ import path from "path"
 import { fileURLToPath, pathToFileURL } from "url"
 import { NamedError } from "@opencode-ai/core/util/error"
 import { Agent as AgentSvc } from "../../src/agent/agent"
+import { BackgroundJob } from "@/background/job"
 import { Bus } from "../../src/bus"
 import { Command } from "../../src/command"
 import { Config } from "@/config/config"
@@ -176,6 +177,7 @@ function makeHttp(input?: { processor?: "blocking" }) {
     lsp,
     mcp,
     AppFileSystem.defaultLayer,
+    BackgroundJob.defaultLayer,
     status,
     SyncEvent.defaultLayer,
   ).pipe(Layer.provideMerge(infra))

packages/opencode/test/session/session.test.ts

@@ -12,6 +12,7 @@ import { Bus } from "@/bus"
 import { Storage } from "@/storage/storage"
 import { SyncEvent } from "@/sync"
 import { RuntimeFlags } from "@/effect/runtime-flags"
+import { BackgroundJob } from "@/background/job"
 
 void Log.init({ print: false })
 
@@ -22,6 +23,7 @@ const it = testEffect(
       Layer.provide(Storage.defaultLayer),
       Layer.provide(SyncEvent.defaultLayer),
       Layer.provide(RuntimeFlags.layer({ experimentalWorkspaces: false })),
+      Layer.provide(BackgroundJob.defaultLayer),
     ),
     CrossSpawnSpawner.defaultLayer,
   ),

packages/opencode/test/session/snapshot-tool-race.test.ts

@@ -30,6 +30,7 @@ import { TestLLMServer } from "../lib/llm-server"
 // Same layer setup as prompt-effect.test.ts
 import { NodeFileSystem } from "@effect/platform-node"
 import { Agent as AgentSvc } from "../../src/agent/agent"
+import { BackgroundJob } from "@/background/job"
 import { Git } from "../../src/git"
 import { Bus } from "../../src/bus"
 import { Command } from "../../src/command"
@@ -125,6 +126,7 @@ function makeHttp() {
     lsp,
     mcp,
     AppFileSystem.defaultLayer,
+    BackgroundJob.defaultLayer,
     status,
     SyncEvent.defaultLayer,
   ).pipe(Layer.provideMerge(infra))