⚡ Bolt: optimize backtest time-series lookups with binary search

[toreleon]

💡 What: Replaced Array.prototype.filter with a custom binary search function (findLastBarIndex) for locating the most recent data point (e.g., price or index value) for a given time threshold in chronologically sorted time-series arrays.
🎯 Why: In the backtest simulator (backtestRunner.ts), time-series data like prices and indexes are queried repeatedly in the inner loop (e.g. for every tick/interval turn, for every candidate ticker). Calling array.filter(b => b.time <= asOf) is an O(n) operation that causes a massive CPU bottleneck given thousands of bars and thousands of queries.
📊 Impact: Reduces time complexity of price overriding and interval index lookups from O(n) to O(log n), vastly improving CPU efficiency and simulator run time.
🔬 Measurement: Verify by running pnpm test tests/tui.test.tsx and timing a backtest simulation or manually running pnpm run test (all 87 tests should pass).

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PR created automatically by Jules for task 7763250888243038433 started by @toreleon

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