⚡ Bolt: Optimize buildCandidate to reduce memory allocations

[toreleon]

💡 What: Replaced intermediate array mapping (.map(), .slice(), .reduce()) in ticker discovery with direct indexing and bound-checked for loops on the original array.
🎯 Why: Iterating over many tickers on large arrays using mapping functions created redundant arrays that had to be garbage collected, creating overhead for the hot discovery loop.
📊 Impact: Expected reduction in garbage collection cycles during ticker discovery as memory allocation is largely reduced.
🔬 Measurement: Validated tests using pnpm test ensuring no calculations were broken.

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PR created automatically by Jules for task 9747253923191451340 started by @toreleon

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