⚡ Bolt: Use chunked MGET for Redis hydration

[d3mocide]

💡 What: Replace pipelined individual GETs with chunked MGET calls (batches of 5000) and increase SCAN count to 5000 when hydrating entities from Redis on poller startup.

🎯 Why: Making individual network round-trips for each entity ID causes a significant N+1 problem, blocking the event loop when dealing with thousands of aircraft during a cold start.

📊 Impact: Reduces network round-trips by roughly a factor of 5000, significantly decreasing cold start latency and event loop blocking overhead.

🔬 Measurement: Verify logs during application startup to observe the faster Redis hydration completion, and note reduced latency/cpu overhead during the "hydrated X aircraft from Redis on startup" phase.

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PR created automatically by Jules for task 10880103225531445295 started by @d3mocide

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