Status: done

# 19 — DOC: Cryptography dependency + test environment note

## What to build

Document and verify test/dev environment setup for wallet crypto paths. `packages/node/meshnet_node/wallet.py` uses `cryptography`; failures occur when `.venv` lacks deps. `cryptography>=41` is already declared in `packages/node/pyproject.toml`, so this issue should focus on documenting the editable-install path and only add root/dev extras if tests still import the node wallet without installing the node package.

**Code refs:**

- `packages/node/pyproject.toml` — `cryptography>=41` (verify declared)
- `packages/node/meshnet_node/wallet.py`
- Handoff: tests fail without `cryptography`, `openai`, `langchain` in `.venv`

## Acceptance criteria

- [x] Confirm `cryptography>=41` remains in node package deps; add to root/dev extras only if tests import wallet without node install
- [x] Add short **Test environment** section to `docs/dev/test-env.md` (or `CONTRIBUTING.md` if created): use `.venv/Scripts/python.exe`, `pip install -e packages/node ...`, optional dep skips
- [x] Note which tests require optional deps (`--ignore=test_openai_gateway,...`)
- [x] No unrelated production code changes

## Blocked by

None

## Resolution

- `packages/node/pyproject.toml` already declared `cryptography>=41` — no change needed.
- `conftest.py` adds every `packages/*` dir to `sys.path`, so first-party imports (e.g. `meshnet_node.wallet`) resolve without an editable install of that package — but third-party deps like `cryptography` still must be installed separately. Added `cryptography>=41` to the root `pyproject.toml` `dev` extra so `pip install -e ".[dev]"` alone covers the wallet tests (`test_node_startup.py`, `test_wallet_binding_proof.py`, `test_devnet_treasury.py`, etc.) without requiring a full `packages/node` install (which would otherwise pull in torch/transformers/accelerate/bitsandbytes).
- Added `docs/dev/test-env.md` with setup instructions (Linux + Windows `.venv\Scripts\python.exe`), and a note on optional-dependency tests: `test_real_model_backend.py` / `test_devnet_treasury.py` use `pytest.importorskip` and skip cleanly; `test_openai_gateway.py` hard-imports `openai`/`langchain_openai` with no skip guard (both already in the `dev` extra) — documented the `--ignore=tests/test_openai_gateway.py` fallback for minimal installs.
- Full suite: 311 passed, 3 skipped, 3 pre-existing failures unrelated to this issue (`test_billing_ledger.py::test_proxy_chat_splits_payout_by_tracker_assigned_route_span`, `test_forfeiture_penalty.py::test_probation_earns_nothing_then_earning_begins`, `test_mining_cli.py::test_legacy_start_without_port_uses_next_available_port` — port-in-use env artifact). Wallet-specific tests (`test_wallet_binding_proof.py`, `test_node_startup.py`, `test_devnet_treasury.py`): 50 passed, 2 skipped.
