feat(integrations): add Intelligence threads to langgraph-fastapi (CopilotKit#5197)

## Summary
- add env-gated CopilotKitIntelligence runtime wiring to
langgraph-fastapi while preserving the FastAPI-specific
LangGraphHttpAgent path
- add the shared Threads drawer/locked panel UI and threadId wiring for
the canvas/chat demo
- bump langgraph-fastapi CopilotKit deps to 1.59.1, add its
package-lock, and document local Intelligence env vars
- remove the temporary langgraph-fastapi parity allowances for
now-verbatim Threads/page/next files
- add a focused batch-2 migration contract test for langgraph-fastapi

## Verification
- confirmed the new migration test failed before implementation
- pnpm exec vitest run
scripts/__tests__/integration-intelligence-migration.test.ts
- pnpm parity:verify --target=langgraph-fastapi (90 ok, 1 existing
next-env.d.ts warning, 0 errors)
- npm run build (in examples/integrations/langgraph-fastapi)
- pnpm exec oxfmt --check <touched TS/TSX/JSON files>
- git diff --check
- commit hook: check-binaries, sync-lockfile, lint-fix,
test-and-check-packages, commitlint
- manual licensed Threads smoke test with local Intelligence composite:
- copied /Users/mothra/Projects/test-signups4/.env into the example .env
and supplied a valid local OPENAI_API_KEY
- docker compose up -d --wait from /Users/mothra/Projects/test-signups4
  - seeded demo-user / 1_demo-user in cpki.users
- started dev with exported .env: set -a; . ./.env; set +a; npm run dev
- /api/copilotkit/info returned mode=intelligence, licenseStatus=valid,
version=1.59.1
  - /api/copilotkit/threads?agentId=default returned 200
  - licensed Threads UI visible
  - selected/restored persisted thread
- created a fresh thread, sent a todo request, agent response rendered,
todo state updated
- refreshed and selected the named thread again; chat history, tool
calls, assistant response, and todo state restored

## Notes
- Targets the PR CopilotKit#5151 lineage branch because batch-2 depends on the
Intelligence foundation from ENT-679.
- The first manual smoke attempt failed because the copied local env had
an empty OPENAI_API_KEY; after replacing it in the ignored example .env
and restarting, the fresh smoke passed.

Author: BenTaylorDev

examples/integrations/_parity/manifest.json

@@ -151,10 +151,7 @@
         "src/app/api/copilotkit/**",
         "docker/Dockerfile.agent",
         "docker-compose.test.yml",
-        "scripts/**",
-        "src/components/threads-drawer/**",
-        "src/app/page.tsx",
-        "next.config.ts"
+        "scripts/**"
       ],
       "packageJsonOverrides": {
         "scripts.dev:agent": "cd agent && uv run main.py",

examples/integrations/langgraph-fastapi/.env.example

@@ -1 +1,8 @@
 AGENT_URL=http://localhost:8000
+OPENAI_API_KEY=
+
+# --- CopilotKit Intelligence (optional; set COPILOTKIT_LICENSE_TOKEN to enable Threads — server + UI) ---
+# COPILOTKIT_LICENSE_TOKEN=
+# INTELLIGENCE_API_URL=http://localhost:4201
+# INTELLIGENCE_GATEWAY_WS_URL=ws://localhost:4401
+# INTELLIGENCE_API_KEY=   # local dev: see examples/integrations/_intelligence/.env.intelligence for the seed value

examples/integrations/langgraph-fastapi/next.config.ts

@@ -3,6 +3,19 @@ import type { NextConfig } from "next";
 const nextConfig: NextConfig = {
   output: "standalone",
   serverExternalPackages: ["@copilotkit/runtime"],
+  env: {
+    // The public Threads UI flag is DERIVED from the server-side license token.
+    // Set COPILOTKIT_LICENSE_TOKEN (only) to enable Threads — do not set this flag
+    // directly. NOTE: NEXT_PUBLIC_* resolves at BUILD time while the runtime reads
+    // the token per-request, so the UI gate and runtime agree only when the token is
+    // present at build time (the standard `next dev` / host-build flow). For a
+    // standalone/Docker image built without the token and injected at runtime, set
+    // COPILOTKIT_LICENSE_TOKEN at build time too (or gate the UI at runtime) so the
+    // baked flag reflects it.
+    NEXT_PUBLIC_COPILOTKIT_THREADS_ENABLED: process.env.COPILOTKIT_LICENSE_TOKEN
+      ? "true"
+      : "false",
+  },
   typescript: {
     // Docker route override uses HttpAgent which has a type mismatch with CopilotRuntime
     ignoreBuildErrors: true,