feat(temporal): support per-node-type taskQueue routing

[tbrandenburg]

Issues fixed

Closes #141 — Support per-node-type activity worker routing (dedicated Docker images/tools per node type)

Summary

Adds an optional taskQueue field to the per-node-type ActivityProfile, so a specific node type's activity can be pinned to a non-default Temporal task queue and served by a dedicated, minimal worker process/Docker image — while every other node type keeps running exactly as today on the shared worker. Fully additive/backward-compatible: no taskQueue in a profile means the current behavior.

Changes:

• packages/temporal: ActivityProfile.taskQueue?: string, validated (non-empty string) in profile-validation.ts, forwarded by resolveFromValidatedProfiles into the options handed to proxyActivities (only when present). Added findProfilesWithUnpolledTaskQueue, the worker-side check for a profile routed to a queue nobody polls (mirrors the existing findProfilesWithoutExecutor).
• apps/execution-worker: new activity-only entrypoint specialized-worker.ts (no workflowsPath) that registers only the AI-agent executor as the illustrative "needs its own image" example, polling a new SPECIALIZED_TASK_QUEUE.
• deploy/ai-studio: new worker-specialized compose service reusing the existing runtime image/target with its own command and env — no new Dockerfile stage needed since the specialized worker is still plain TS on the same base image.
• READMEs updated in packages/temporal, apps/execution-worker, deploy/ai-studio.

No changes to runGraph, the graph interpreter, the UI, the DB schema, or the backend — purely a worker-topology/deployment change, per the issue's non-goals.

Validation commands run

• pnpm build:temporal
• pnpm -F @workflowbuilder/temporal test — 9 files / 92 tests passed
• pnpm -F @workflowbuilder/temporal typecheck / lint — clean
• pnpm -F execution-worker typecheck / lint / test — clean, 3 files / 10 tests passed
• pnpm exec prettier --check packages/temporal apps/execution-worker deploy/ai-studio — clean
• pnpm test (full monorepo, all workspaces) — all passing

E2E coverage

packages/temporal/test/task-queue-routing.test.ts is a real end-to-end test: it spins up a real TestWorkflowEnvironment (real embedded Temporal server, no mocks), runs an actual workflow with a node profile carrying taskQueue, and asserts against the real recorded Event History that the ActivityTaskScheduled command for that node names the specialized queue rather than the workflow's default queue.

Risks / follow-ups

• findProfilesWithUnpolledTaskQueue is exported but not auto-wired into WorkflowBuilderPlugin's constructor (unlike findProfilesWithoutExecutor), since that would require the plugin to know about every queue in a multi-worker deployment. Left as a standalone check a consumer calls explicitly — documented in the package README.
• worker-specialized and specialized-worker.ts are illustrative reference implementations (routes ai-studio/ai-agent as the example specialized node type); no node type in this app is actually configured with taskQueue today, so the service idles until an app opts a node type in via nodeActivityProfiles.
• No unrelated issues found during this work.

[tbrandenburg]

Ran the full pr-check.yml suite independently on my fork (fork PRs need a maintainer to approve the workflow run on this repo before it executes here) — all 6 jobs pass, including the Temporal plugin job covering this change: https://github.com/tbrandenburg/workflowbuilder/actions/runs/34834106741

• Execution pipeline lint + typecheck + test — pass
• Format check — pass
• SDK lint + typecheck + test + build — pass
• Starter build — pass
• Temporal plugin lint + typecheck + test + build — pass
• UI + UI tokens lint + typecheck + test + build — pass

Happy to answer questions or make changes based on review.