fix(ui): theme the created-key box so it follows dark mode (#37985)

The virtual key shown after creating a key sits in a div with a
hardcoded #f8f8f8 inline background, so in dark mode the box keeps
the light background while the key text inherits the light foreground
color, leaving the key nearly unreadable. Swap the inline styles for
the bg-muted and text-foreground tokens, which resolve per theme.

ui/litellm-dashboard/src/components/shared/CreatedKeyDisplay.test.tsx

@@ -19,6 +19,15 @@ describe("CreatedKeyDisplay", () => {
     expect(screen.getByText("sk-test-123")).toBeInTheDocument();
   });
 
+  it("should theme the key box with tokens instead of a hardcoded light background", () => {
+    render(<CreatedKeyDisplay apiKey="sk-test-123" />);
+
+    const keyBox = screen.getByText("sk-test-123").parentElement as HTMLElement;
+
+    expect(keyBox).not.toHaveAttribute("style");
+    expect(keyBox).toHaveClass("bg-muted");
+  });
+
   it("should display the security warning", () => {
     render(<CreatedKeyDisplay apiKey="sk-test-123" />);
     expect(screen.getByText(/you will not be able to view it again/i)).toBeInTheDocument();

ui/litellm-dashboard/src/components/shared/CreatedKeyDisplay.tsx

@@ -29,15 +29,8 @@ const CreatedKeyDisplay: React.FC<CreatedKeyDisplayProps> = ({ apiKey }) => {
       </p>
 
       <p className="text-sm text-muted-foreground mt-3 mb-1">Virtual Key:</p>
-      <div
-        style={{
-          background: "#f8f8f8",
-          padding: "10px",
-          borderRadius: "5px",
-          marginBottom: "10px",
-        }}
-      >
-        <pre style={{ wordWrap: "break-word", whiteSpace: "normal", margin: 0 }}>{apiKey}</pre>
+      <div className="bg-muted rounded-md p-2.5 mb-2.5">
+        <pre className="m-0 whitespace-normal break-words text-foreground">{apiKey}</pre>
       </div>
 
       <CopyToClipboard text={apiKey} onCopy={handleCopy}>