⚡ Bolt: Optimize KnowledgeGraph search and node filtering

[hadsern]

💡 What: Pre-indexed nodes into a Map (nodeMap) and a pre-lowercased string array (searchableNodes) within the filtered useMemo block in KnowledgeGraph.tsx. This avoids repeatedly iterating the entire node list and allocating massive amounts of new toLowerCase() strings on every single keydown stroke.
🎯 Why: Filtering nodes array and continuously executing toLowerCase() strings inside array iterations causes heavy CPU pressure and UI typing lag when the user queries large node datasets within the component.
📊 Impact: Changing the text search loop to use pre-lowercased strings, and the specific exact-match node focus lookups to a Map provides an O(1) performance and drastically removes O(N) array-scanning overheads and repetitive garbage collection from the main thread during typing events.
🔬 Measurement: Verify optimization by interacting with the Filter/Find inputs in the KnowledgeGraph component and confirming no functional changes to search behavior but with eliminated toLowerCase string processing overheads.

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PR created automatically by Jules for task 4897619608573371061 started by @hadsern

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