ui-svelte: fix histogram calculation (#695)

- Fix the histogram calculation to use server provided generation
tokens/second.
- Move histogram to Activities page where it can exist with the rest of
the token metrics

Fixes #681

ui-svelte/src/routes/Models.svelte

@@ -2,7 +2,6 @@
   import { isNarrow } from "../stores/theme";
   import { upstreamLogs } from "../stores/api";
   import ModelsPanel from "../components/ModelsPanel.svelte";
-  import StatsPanel from "../components/StatsPanel.svelte";
   import LogPanel from "../components/LogPanel.svelte";
   import ResizablePanels from "../components/ResizablePanels.svelte";
 
@@ -14,13 +13,6 @@
     <ModelsPanel />
   {/snippet}
   {#snippet rightPanel()}
-    <div class="flex flex-col h-full space-y-4">
-      {#if direction === "horizontal"}
-        <StatsPanel />
-      {/if}
-      <div class="flex-1 min-h-0">
-        <LogPanel id="modelsupstream" title="Upstream Logs" logData={$upstreamLogs} />
-      </div>
-    </div>
+    <LogPanel id="modelsupstream" title="Upstream Logs" logData={$upstreamLogs} />
   {/snippet}
 </ResizablePanels>