fix(strategy-center): enable live trading mode for crypto portfolios (#225)

[mwaleedta]

Summary

Fixes OpenByteInc/QuantDinger#225.

The web deployment editor was blocking executionMode=live for any Strategy API V2 portfolio unless the asset class was USStock, even though the backend explicitly supports same-market live deployments (see backend_api_python/app/services/strategy_v2/deployment.py::_validate_execution_account — Crypto + USStock both pass; only mixed-market is rejected).

For a multi-instrument crypto portfolio (e.g. BTC/USDT@swap + ETH/USDT@swap), users could only choose signal mode in the deployment wizard. Single-instrument CTA crypto strategies worked fine.

Root cause

In src/views/strategy-center/components/LiveStrategyEditor.vue:

• supportsLive (line 370) hard-coded isPortfolioStrategy → marketCategory === 'USStock', disabling the radio for crypto portfolios.
• compatibleCredentials (line 420) hard-coded isPortfolioStrategy → exchange === 'alpaca', hiding binance/okx/etc. credentials.

Fix

Two surgical changes:

1. supportsLive now delegates to supportsLiveExecutionMode(manifest) — permits any same-market Crypto or USStock manifest, regardless of strategy type.
2. compatibleCredentials now delegates to credentialMatchesLiveStrategy(manifest, exchange_id) — accepts crypto exchanges for Crypto manifests, alpaca/ibkr for USStock manifests, rejects everything else.

Both helpers live in a new src/utils/liveTradingEligibility.js module so they can be unit-tested without mounting the Vue SFC.

Tests

• 10 new exhaustive specs in tests/unit/liveTradingEligibility.test.mjs covering CTA vs. portfolio × Crypto/USStock/mixed and credential matching across the supported exchanges.
• Extended tests/unit/liveStrategyCurrentContract.test.mjs with a source-scan regression test that asserts the old hard-blocks are gone and the new helpers are wired in.
• Full pnpm test:unit passes (55/55), plus the new files run 13/13 green.

Verification

Per the issue's repro, a strategy like:

def initialize(context):
    context.set_universe([
        "Crypto:BTC/USDT@swap",
        "Crypto:ETH/USDT@swap",
    ])
    context.subscribe(frequency="4h")

...now shows "Live Automated Trading" as an available option in the deploy wizard and accepts a crypto exchange credential.

Out of scope

• IBKR for USStock portfolios (still alpaca-credentialed in the portfolio picker — unchanged, separate concern).
• Mixed-market portfolios still blocked, matching the backend's strategyV2.mixedMarketLiveUnsupported.