test: add SENSEX hardening unit tests and fix market close exit window

[kunalrbhatia]

Incident Summary & Hardening Review

This PR adds unit tests, closes remaining operational and code gaps, and provides regression verification for the 20-Aug-2026 SENSEX expiry launch incident.

Key Gaps Closed & Improvements Made:

1. Market Close Exit Window Bug (isMarketClosed):

   • isMarketClosed() previously hardcoded { hours: 15, minutes: 30 } as market close cutoff.
   • On 20-Aug, when EXIT_TIME was set past 15:30 (e.g. 15:35), isMarketClosed() evaluated to true, causing isTradeAllowed() to fail with Conditions not right... Reasons: Market closed. Because executeTrade() was gated behind isTradeAllowed(), closeTrade() never ran automatically.
   • Fix: isMarketClosed() now evaluates upper bound using appConfig.exitTime (defaulting to 15:40 F&O close bound). checkMarketConditionsAndExecuteTrade also allows execution if past exit time so trade close is never blocked by market entry gates.

2. Roll Decision Logging & Strikeprice Data-Integrity Guard (repeatShortStraddle):

   • Added comprehensive roll decision input logging (difference, strikeDiff, isSameStrikeAlreadyTraded, cepe_present, previousTradeStrikePrice, atmStrike) before any branching decisions.
   • Added explicit data-integrity guards: if any open position carries strikeprice === '0' or unparseable strike, or if previousTradeStrikePrice === 0, the roll decision is skipped with a warning.
   • Updated updateLivePositions so existing positions also refresh strikeprice and optiontype if previously invalid.

3. NODE_ENV / Jest Execution Gate for File Writes:

   • Gated writeToFile in src/helpers/logger.ts and scrip master cache file writes in src/helpers/apiService/marketData.ts on process.env.NODE_ENV !== 'test'.
   • Running Jest tests locally or in CI no longer corrupts production log files or overwrites scripMaster.json.

4. Exchange Resolution & Code Commenting:

   • Confirmed doOrder exchange resolution (exchange || getExchangeForIndex(...)) is applied only as fallback when exchange is omitted.
   • Documented the known FPI regex limitation (NIFTYFPI25AUG261320PE parsing strike as 61320 in FPI segment) in code comments.

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NIFTY Regression Evidence

1. Regex Equivalence on NIFTY:
   • Verified across all OPTIDX symbols starting with NIFTY (excluding FPI) against scripMaster.json (156,812 scrips):
   • 0 mismatches found across 2,758 NIFTY option symbols between the old anchored regex /^([A-Z]+)(\d{2}[A-Z]{3}\d{2})(\d+\.?\d*)([CP]E)$/ and the new suffix regex /(\d{5})([CP]E)$/.
2. Exchange Resolution on NIFTY:
   • getExchangeForIndex('NIFTY') returns 'NFO'.
3. Session Flag on NIFTY:
   • Behavior is strictly more accurate: failed NIFTY SELL legs leave straddleOpenedToday as false to enable retry on the next tick.
4. Full Test Suite Verification:
   • pnpm verify suite (pnpm format; pnpm lint; pnpm typecheck; pnpm test; pnpm build) runs 100% green (24 test suites, 277 tests passing).

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Collector Throttling (Ops / Deployment Note)

• Issue: optionchain-live and sensex-live PM2 daemons poll SmartAPI every 10s using API key K94372, causing rate limit 403 HTTP errors during live algo order placement.
• Ops Recommendation: Increase gateway collector polling sleep in src/live.js and src/sensex-live.js from 10s (10000) to 5 minutes (300000), or rely on the 5-minute collect-once.js cron during expiry day trading windows (9:15–15:40 IST).