debug(chart): add cache logging to debug cache misses

memento-note/lib/ai/services/chart-suggestion.service.ts

@@ -70,11 +70,16 @@ function setCached(key: string, data: SuggestChartsResponse): void {
 export async function suggestCharts(request: SuggestChartsRequest): Promise<SuggestChartsResponse> {
   // Check cache first
   const cacheKey = getCacheKey(request.content || '', request.selection)
+  console.log('[suggestCharts] Cache key:', cacheKey, 'contentLen:', request.content?.length, 'selectionLen:', request.selection?.length)
+
   const cached = getCached(cacheKey)
   if (cached) {
+    console.log('[suggestCharts] CACHE HIT - returning cached data')
     return cached
   }
 
+  console.log('[suggestCharts] CACHE MISS - calling API')
+
   try {
     const response = await fetch('/api/ai/suggest-charts', {
       method: 'POST',
@@ -104,6 +109,9 @@ export async function suggestCharts(request: SuggestChartsRequest): Promise<Sugg
     // Cache successful responses
     if (!data.error && !data.quotaExceeded) {
       setCached(cacheKey, data)
+      console.log('[suggestCharts] Cached response for key:', cacheKey, 'cache size now:', cache.size)
+    } else {
+      console.log('[suggestCharts] NOT caching (has error or quota exceeded)')
     }
 
     return data