Fix API errors and improve customer discovery with real web results

- Fix usage/stats 500: use Date() not datetime.date() for SQL cast
- Fix customers 422: raise size limit to 1000
- Replace unreliable MCP client with direct Bing batch search for discovery
- Batch all search queries in one browser session (faster)
- Show real company names/URLs from Bing, not generic templates
- Smart filter for non-business results (news, blogs, forums)
- Fallback suggestions when search results are insufficient
- Frontend: clickable contact URLs, provider indicator, better layout

backend/app/ai/providers/nvidia.py

@@ -28,10 +28,11 @@ class NvidiaProvider(OpenAIProvider):
         messages.append({"role": "user", "content": message})
         t1 = time.time()
 
+        max_tokens = 800 if "JSON" in (system or "").upper() else 300
         kwargs = {
             "model": self.model,
             "messages": messages,
-            "max_tokens": 300,
+            "max_tokens": max_tokens,
             "temperature": 0.3,
         }
         resp = await self.client.chat.completions.create(**kwargs)