⚡ Bolt: Optimize view model collection updates

[acebytes]

💡 What: Replaced for loops that mutate individual elements of @Published arrays (scanResults, nodeModulesItems) with .map functions in CacheoutViewModel.swift. Also added explicit comments explaining the optimization.

🎯 Why: Mutating an element of a @Published array in-place triggers objectWillChange and a corresponding UI view re-render for every single iteration of the loop. This can cause severe stuttering when selecting or deselecting many cache items at once.

📊 Impact: Reduces property change notifications from O(N) to O(1) per function call. The UI will now recalculate exactly once per bulk selection/deselection action.

🔬 Measurement: Select "Smart Clean" or select/deselect all node_modules items with many projects loaded. The UI will respond instantly without queuing up N separate render passes.

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PR created automatically by Jules for task 5025282328415269806 started by @acebytes

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