Harden demo scripts: dead eth-account import, nonce, success-check

[Valisthea]

Summary

The demo/ scripts are what integrators copy to build bots that hold API-wallet keys and move funds, so a small defect here propagates widely. This PR fixes three issues that bite on a fresh setup and pins runnable dependencies.

All changes are client-side only and do not alter any byte the server verifies. EIP-712 / HMAC signatures are byte-identical before and after — cross-checked against ethers.signTypedData (see Verification).

Fixes

1. Demos fail to import on a current eth-account

aster-code.py and sol_agent.py import encode_structured_data, which was removed in eth-account >= 0.13 (replaced by encode_typed_data). A fresh pip install eth-account makes the demos crash with ImportError before anything is sent. Both are migrated to encode_typed_data(full_message=...).

2. Nonce can collide and get rejected as -4225 Nonce Expired

get_nonce() used int(time.time()) * 1_000_000, i.e. 1-second resolution (the docs state microsecond precision). Two workers — or one process restarted — sharing a single API wallet emit the same nonce within the same second, and the server rejects the duplicate (-4225 Nonce Expired). aster-code.py also had no lock. Now uses microsecond time.time_ns() // 1000, mutex-guarded and strictly monotonic, so a nonce is never reused within a process. (Across multiple processes, still use one nonce source per key.)

3. consolidation.js reports success on failure

if (sendToMainAddressRes['status'] = 'SUCCESS') is an assignment, not a comparison, so the consolidation step always logs success — even when the transfer failed. The withdraw check spotWithdraw['hash'] != '' also dereferences an error return (''). Fixed to === and added guards so a failed transfer or withdraw is reported as a failure.

4. Minor

• sol_agent.py: print the nonce that was actually sent, instead of calling get_nonce() a second time (which produced a different value than the one signed).
• Added demo/requirements.txt and demo/package.json pinning runnable dependency versions.

Verification

• python -m py_compile and node --check pass on all demo files.
• Signature parity: signing the same payload with the migrated Python (encode_typed_data) and with ethers.signTypedData produces identical signatures for both the Message{msg} scheme and the dynamic action struct — so the migration stays wire-compatible with the live API.
• The patched nonce is strictly monotonic and unique across a 50,000-call burst.

Intentionally not changed (needs server-side coordination)

These are genuine hardening opportunities, but changing them client-side would break verification against the current backend, so they are left for a coordinated follow-up rather than silently altered here:

• Value-inferred EIP-712 types in sign_v3_eip712: the field type depends on the literal (canWithdraw=False vs 0 sign to different digests). A fixed per-action schema would be more robust.
• Domain chainId hardcoded to 56 on the main-account path, with verifyingContract = 0x0 — the EIP-712 domain does not bind the operating chain.
• personal_sign("You are signing into Astherus {nonce}") authorizes API-key creation and is byte-identical to the login message. EIP-712 typed data would let wallets show users what they are actually authorizing.