⚡ Bolt: Replace array allocations with string concatenation in search

.jules/bolt.md

@@ -60,3 +60,6 @@ Optimized metric route processing to O(N) by creating a mapping of routes direct
 ## 2026-06-25 - Avoid Map allocations in frontend ERD loops and mutate asyncpg records in-place
 **Learning:** The frontend `snapshotToGraph` iterates over thousands of columns to generate the graph, so repeated lookups and redundant collection assignments increase GC pressure. Backend snapshot column dictionaries are freshly instantiated for the payload, so `add_column_examples` can safely fill missing fields in place.
 **Action:** Reuse existing collections while aggregating relational data, create `Map`/`Set` entries only on first use, and check for missing example fields before calling expensive inference helpers.
+## 2026-07-06 - Avoid array allocations for string building in loops
+**Learning:** Using `.flatMap()`, array spread syntax (`...`), and `.join()` for building large strings inside React hooks iterating over ERD nodes creates unnecessary array allocations and increases garbage collection overhead.
+**Action:** Use iterative string concatenation (`+=`) instead of array creation methods when building complex strings inside loops.

frontend/src/App.tsx

@@ -182,18 +182,13 @@ export default function App() {
     if (!normalizedNodeSearch) return new Set<string>();
     const matches = new Set<string>();
     for (const node of nodes) {
-      const haystack = [
-        node.data.title,
-        node.data.comment ?? "",
-        ...node.data.columns.flatMap((column) => [
-          column.column_name,
-          column.data_type,
-          column.column_comment ?? "",
-        ]),
-      ]
-        .join(" ")
-        .toLocaleLowerCase();
-      if (haystack.includes(normalizedNodeSearch)) {
+      // ⚡ Bolt: Build search haystack using string concatenation instead of array allocations
+      // (.flatMap, spread syntax, .join) to significantly reduce GC overhead during frequent React hook executions.
+      let haystack = node.data.title + " " + (node.data.comment ?? "");
+      for (const column of node.data.columns) {
+        haystack += " " + column.column_name + " " + column.data_type + " " + (column.column_comment ?? "");
+      }
+      if (haystack.toLocaleLowerCase().includes(normalizedNodeSearch)) {
         matches.add(node.id);
       }
     }