Fix query mode grouping in performance metrics

- Add queryMode field to QueryLogSummary interface
- Update getQueryLogs to group by both query AND queryMode
- Use composite key (query|||queryMode) for proper separation
- Enables separate tracking of Pure RAG vs Graph Search queries

Previously, queries with the same text but different modes were
merged together, causing metrics to only show one aggregate value.
Now each mode's performance is tracked independently.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

nvidia/txt2kg/assets/frontend/lib/query-logger.ts

@@ -17,6 +17,7 @@ export interface QueryLogEntry {
 
 export interface QueryLogSummary {
   query: string;
+  queryMode: 'traditional' | 'vector-search' | 'pure-rag';
   count: number;
   firstQueried: string;
   lastQueried: string;
@@ -148,9 +149,10 @@ export class QueryLoggerService {
         return [];
       }
 
-      // Group logs by query
+      // Group logs by query AND queryMode
       const querySummaries = new Map<string, {
         query: string;
+        queryMode: 'traditional' | 'vector-search' | 'pure-rag';
         count: number;
         timestamps: string[];
         executionTimes: number[];
@@ -161,8 +163,11 @@ export class QueryLoggerService {
       }>();
 
       logs.forEach(entry => {
-        const existing = querySummaries.get(entry.query) || {
+        // Use composite key: query + mode
+        const key = `${entry.query}|||${entry.queryMode}`;
+        const existing = querySummaries.get(key) || {
           query: entry.query,
+          queryMode: entry.queryMode,
           count: 0,
           timestamps: [],
           executionTimes: [],
@@ -180,12 +185,13 @@ export class QueryLoggerService {
         if (entry.metrics.recall !== undefined) existing.recalls.push(entry.metrics.recall);
         existing.resultCounts.push(entry.metrics.resultCount);
 
-        querySummaries.set(entry.query, existing);
+        querySummaries.set(key, existing);
       });
 
       // Convert to array and format
       const result: QueryLogSummary[] = Array.from(querySummaries.values()).map(summary => ({
         query: summary.query,
+        queryMode: summary.queryMode,
         count: summary.count,
         firstQueried: summary.timestamps[0],
         lastQueried: summary.timestamps[summary.timestamps.length - 1],