⚡ Bolt: Reduce GC pressure in Naver map marker materializations

[ClarusIubar]

💡 What: Replaced functional .map(), .filter(Boolean), and spread syntaxes (...) with explicit for...of loops, Set.add(), and operations.push() inside the Naver marker batch updating useEffect.

🎯 Why: During rapid map panning, the hook generated numerous intermediate arrays simultaneously (for nextIds, visibleSignature, placeById, and batch map operations). This caused excessive memory allocation and immediate GC pressure, leading to UI jank in hot rendering paths.

📊 Impact: Significantly reduces O(N) memory allocations and intermediate closure instances inside the hot viewport rendering path, resulting in smoother panning performance on lower-end devices.

🔬 Measurement: Panning rapidly with multiple overlaid map categories active will show visibly fewer stuttering frames in Chrome performance tools, as less time is spent collecting intermediate arrays.

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PR created automatically by Jules for task 8730619022283415500 started by @ClarusIubar

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