feat: refresh OpenVINO GenAI NPU worker prototype

openvino-genai-npu-worker/README.md

@@ -18,6 +18,7 @@ The worker does not write memory, does not restart Atlas/Hermes, does not change
 - `CONTRACT.md` — bounded-worker service contract, endpoint/CLI API, smoke plan, NPU verification, docs implications, and no-go criteria.
 - `worker.py` — stdlib HTTP API plus CLI wrapper.
 - `smoke_llm_npu.py` — direct GenAI smoke test with NPU busy-time verification.
+- `tests/test_worker.py` — unit tests with a fake GenAI pipeline and synthetic busy-time counter.
 - `systemd/openvino-genai-npu-worker.service` — optional user-service template; not installed by this prototype.
 
 ## Model/cache
@@ -73,15 +74,20 @@ Observed cold-ish smoke after download/cache setup:
   --input 'Kanban task asks for a small OpenVINO GenAI NPU worker prototype.'
 ```
 
+Exit code is non-zero if validation fails, generation fails, or the worker-reported `npu_busy_delta_us` is not positive.
+
 ## HTTP usage
 
 Start locally only:
 
 ```bash
 cd /home/will/lab/swarm/openvino-genai-npu-worker
+ss -ltnp | grep ':18820' && { echo 'port 18820 already in use'; exit 1; } || true
 /home/will/.venvs/npu/bin/python worker.py --host 127.0.0.1 --port 18820
 ```
 
+The server also refuses startup if a listener is already accepting connections on `127.0.0.1:18820`.
+
 Endpoints:
 
 ```text
@@ -103,6 +109,26 @@ curl -s http://127.0.0.1:18820/v1/worker/generate \
 
 Response includes `npu_busy_delta_us`; treat zero as failure even if HTTP status is 200.
 
+## Unit tests
+
+These tests use only synthetic strings and a fake GenAI pipeline, so they do not load the model or touch private data:
+
+```bash
+cd /home/will/lab/swarm/openvino-genai-npu-worker
+python -m pytest -q
+```
+
+## Environment variables
+
+```text
+OV_GENAI_NPU_MODEL=/home/will/models/openvino-genai/Qwen2.5-1.5B-Instruct-int4-ov
+OV_GENAI_NPU_CACHE=/home/will/.cache/openvino/genai-npu/qwen2.5-1.5b-int4
+OV_GENAI_NPU_HOST=127.0.0.1
+OV_GENAI_NPU_PORT=18820
+```
+
+Only `127.0.0.1` is accepted by the current prototype; wider binds require an explicit code change and approval.
+
 ## Safety boundaries
 
 - Binds only to `127.0.0.1` by default; non-local bind is refused in code.