feat(UI): Adding a session manager (#3203)

# What does this PR do?

- Introduces the Agent Session creation for the Playground and allows
users to set tools
- note tools are actually not usable yet and this is marked explicitly
- this also caches sessions locally for faster loading on the UI and
deletes them appropriately
   - allows users to easily create new sessions as well
- Moved Model Configuration settings and "System Message" / Prompt to
the left component
- Added new logo and favicon
- Added new typing animation when LLM is generating

### Create New Session
<img width="1916" height="1393" alt="Screenshot 2025-08-21 at 4 18
08 PM"
src="https://github.com/user-attachments/assets/52c70ae3-a33e-4338-8522-8184c692c320"
/>


### List of Sessions
<img width="1920" height="1391" alt="Screenshot 2025-08-21 at 4 18
56 PM"
src="https://github.com/user-attachments/assets/ed78c3c6-08ec-486c-8bad-9b7382c11360"
/>

<!-- If resolving an issue, uncomment and update the line below -->
<!-- Closes #[issue-number] -->

## Test Plan
Unit tests added

---------

Signed-off-by: Francisco Javier Arceo <farceo@redhat.com>

llama_stack/ui/app/globals.css

@@ -120,3 +120,44 @@
     @apply bg-background text-foreground;
   }
 }
+
+@layer utilities {
+  .animate-typing-dot-1 {
+    animation: typing-dot-bounce-1 0.8s cubic-bezier(0.4, 0, 0.6, 1) infinite;
+  }
+
+  .animate-typing-dot-2 {
+    animation: typing-dot-bounce-2 0.8s cubic-bezier(0.4, 0, 0.6, 1) infinite;
+  }
+
+  .animate-typing-dot-3 {
+    animation: typing-dot-bounce-3 0.8s cubic-bezier(0.4, 0, 0.6, 1) infinite;
+  }
+
+  @keyframes typing-dot-bounce-1 {
+    0%, 15%, 85%, 100% {
+      transform: translateY(0);
+    }
+    7.5% {
+      transform: translateY(-6px);
+    }
+  }
+
+  @keyframes typing-dot-bounce-2 {
+    0%, 15%, 35%, 85%, 100% {
+      transform: translateY(0);
+    }
+    25% {
+      transform: translateY(-6px);
+    }
+  }
+
+  @keyframes typing-dot-bounce-3 {
+    0%, 35%, 55%, 85%, 100% {
+      transform: translateY(0);
+    }
+    45% {
+      transform: translateY(-6px);
+    }
+  }
+}