fix: address issues in model pull and chat API

- Refactored model pull logic to improve error handling and user feedback.
- Enhanced chat API to ensure better performance and reliability during message fetching.
- Updated UI components for a more intuitive user experience when interacting with models and messages.

data/models/llama2.json

@@ -0,0 +1,32 @@
+{
+  "model": "llama2",
+  "url": "https://ollama.com/library/llama2",
+  "description": "Llama 2 is a collection of foundation language models ranging from 7B to 70B parameters.",
+  "variantsCount": 4,
+  "variants": [
+    {
+      "name": "llama2:latest",
+      "size": "3.8GB",
+      "context": "4K",
+      "inputType": "Text"
+    },
+    {
+      "name": "llama2:7b",
+      "size": "3.8GB",
+      "context": "4K",
+      "inputType": "Text"
+    },
+    {
+      "name": "llama2:13b",
+      "size": "7.4GB",
+      "context": "4K",
+      "inputType": "Text"
+    },
+    {
+      "name": "llama2:70b",
+      "size": "39GB",
+      "context": "4K",
+      "inputType": "Text"
+    }
+  ]
+}