feat(core): add integration-backed search

packages/core/test/form.test.ts

@@ -4,6 +4,7 @@ import { AppNodeBuilder } from "@opencode-ai/core/effect/app-node-builder"
 import { LayerNode } from "@opencode-ai/core/effect/layer-node"
 import { EventV2 } from "@opencode-ai/core/event"
 import { Form } from "@opencode-ai/core/form"
+import { Integration } from "@opencode-ai/core/integration"
 import { SessionSchema } from "@opencode-ai/core/session/schema"
 import { testEffect } from "./lib/effect"
 
@@ -59,6 +60,27 @@ describe("Form", () => {
     }),
   )
 
+  it.effect("uses an empty reply to complete an integration form", () =>
+    Effect.gen(function* () {
+      const service = yield* Form.Service
+      const created = yield* service.create({
+        sessionID: "ses_test",
+        mode: "integration",
+        integrationID: Integration.ID.make("exa"),
+      })
+
+      const invalid = yield* service.reply({ id: created.id, answer: { connected: true } }).pipe(Effect.flip)
+      expect(invalid).toEqual(
+        new Form.InvalidAnswerError({
+          id: created.id,
+          message: "Integration forms must be answered with an empty answer",
+        }),
+      )
+      yield* service.reply({ id: created.id, answer: {} })
+      expect(yield* service.state(created.id)).toEqual({ status: "answered", answer: {} })
+    }),
+  )
+
   it.effect("gates required fields and rejects inactive answers via when", () =>
     Effect.gen(function* () {
       const service = yield* Form.Service