fix(instance): run bootstrap from instance store (#25475)

packages/opencode/test/agent/plugin-agent-regression.test.ts

@@ -0,0 +1,51 @@
+import { afterEach, expect, test } from "bun:test"
+import path from "path"
+import { pathToFileURL } from "url"
+import { AppRuntime } from "../../src/effect/app-runtime"
+import { Agent } from "../../src/agent/agent"
+import { Instance } from "../../src/project/instance"
+import { disposeAllInstances, tmpdir } from "../fixture/fixture"
+
+afterEach(async () => {
+  await disposeAllInstances()
+})
+
+test("plugin-registered agents appear in Agent.list", async () => {
+  await using tmp = await tmpdir({
+    init: async (dir) => {
+      const pluginFile = path.join(dir, "plugin.ts")
+      await Bun.write(
+        pluginFile,
+        [
+          "export default async () => ({",
+          "  config: async (cfg) => {",
+          "    cfg.agent = cfg.agent ?? {}",
+          "    cfg.agent.plugin_added = {",
+          '      description: "Added by a plugin via the config hook",',
+          '      mode: "subagent",',
+          "    }",
+          "  },",
+          "})",
+          "",
+        ].join("\n"),
+      )
+      await Bun.write(
+        path.join(dir, "opencode.json"),
+        JSON.stringify({
+          $schema: "https://opencode.ai/config.json",
+          plugin: [pathToFileURL(pluginFile).href],
+        }),
+      )
+    },
+  })
+
+  await Instance.provide({
+    directory: tmp.path,
+    fn: async () => {
+      const agents = await AppRuntime.runPromise(Agent.Service.use((svc) => svc.list()))
+      const added = agents.find((agent) => agent.name === "plugin_added")
+      expect(added?.description).toBe("Added by a plugin via the config hook")
+      expect(added?.mode).toBe("subagent")
+    },
+  })
+})