feat: implement real-time websocket exit engine daemon

[kunalrbhatia]

Motivation & Problem

• 403 Rate-Limit Wars (20-Aug, 25-Aug): REST LTP polling bursts hit rate limits on shared API keys. Angel SmartStream WebSocket LTP push does NOT consume the REST rate window.
• 5-Minute Exit Latency: 1-Sep incident demonstrated that a 5-minute cron poll can miss rapid premium spikes (e.g. NIFTY 24000 CE breached 130.8 trigger sub-second, but REST cron only closed it at 131.65 five minutes later).
• CAS Pre-Auction Window (15:15–15:35): Premium doubling can occur between 5-minute REST ticks.

Key Changes

• WebSocket Feed (src/helpers/apiService/marketFeed.ts): Connects to Angel WebSocketV2 using login feedToken, auto-reconnects with exponential backoff (2s, 4s, 8s, up to 60s), and normalizes raw tokens (normalizeToken).
• Real-Time Exit Daemon (src/marketFeedDaemon.ts): PM2-supervised background process that subscribes to all position tokens + index spot (NIFTY 99926000 or SENSEX spot), tracks LTPs in memory, recomputes MTM on every tick, and triggers closeBreachedLegs immediately on per-leg stoploss breach (reusing PR fix: guard shouldExitDueToStoploss against zero entry price and ltp #111 zero-guard and PR feat: close only breached leg on stoploss #113 selective leg exit logic).
• Fast-Path MTM (src/helpers/apiService/positions.ts): Extended getMtm with an optional latestPrices map for sub-millisecond in-memory MTM evaluation without REST calls.
• PM2 & CI Integration (ecosystem.config.cjs, .github/workflows/ci.yml): Added smart-api-feed PM2 app with automatic startOrReload during deployment.
• Watchdog Fallback: Retained the existing 5-minute cron watchdog as a secondary safety net.

Verification

• Full verification suite (pnpm format; pnpm lint; pnpm typecheck; pnpm test; pnpm build) passed cleanly.
• Unit tests added in __tests__/helpers/apiService/marketFeed.test.ts and __tests__/marketFeedDaemon.test.ts (306/306 tests passing).
• Smoke test verified against WebSocketV2 API connection and token normalization.