feat: add SettingsTabBar component for primary/fallback settings tabs

Minimal pill-style tab bar for switching between primary and fallback
model parameter views inside the InlineParameterPanel.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

src/components/nodes/SettingsTabBar.tsx

@@ -0,0 +1,46 @@
+import React from "react";
+
+interface SettingsTabBarProps {
+  activeTab: "primary" | "fallback";
+  onTabChange: (tab: "primary" | "fallback") => void;
+  primaryLabel: string;
+  fallbackLabel: string;
+}
+
+export function SettingsTabBar({
+  activeTab,
+  onTabChange,
+  primaryLabel,
+  fallbackLabel,
+}: SettingsTabBarProps) {
+  return (
+    <div className="flex gap-1 mb-2">
+      <button
+        type="button"
+        className={`text-[10px] px-2 py-0.5 rounded transition-colors ${
+          activeTab === "primary"
+            ? "bg-neutral-700 text-neutral-200"
+            : "bg-transparent text-neutral-500 hover:text-neutral-400"
+        }`}
+        onClick={() => {
+          if (activeTab !== "primary") onTabChange("primary");
+        }}
+      >
+        {primaryLabel}
+      </button>
+      <button
+        type="button"
+        className={`text-[10px] px-2 py-0.5 rounded transition-colors ${
+          activeTab === "fallback"
+            ? "bg-neutral-700 text-neutral-200"
+            : "bg-transparent text-neutral-500 hover:text-neutral-400"
+        }`}
+        onClick={() => {
+          if (activeTab !== "fallback") onTabChange("fallback");
+        }}
+      >
+        {fallbackLabel}
+      </button>
+    </div>
+  );
+}

src/components/nodes/__tests__/SettingsTabBar.test.tsx

@@ -0,0 +1,67 @@
+import { describe, it, expect, vi } from "vitest";
+import { render, screen, fireEvent } from "@testing-library/react";
+import { SettingsTabBar } from "../SettingsTabBar";
+
+describe("SettingsTabBar", () => {
+  it("renders both tab labels", () => {
+    render(
+      <SettingsTabBar
+        activeTab="primary"
+        onTabChange={vi.fn()}
+        primaryLabel="Nano Banana"
+        fallbackLabel="Flux Dev"
+      />
+    );
+
+    expect(screen.getByText("Nano Banana")).toBeInTheDocument();
+    expect(screen.getByText("Flux Dev")).toBeInTheDocument();
+  });
+
+  it("highlights active tab", () => {
+    render(
+      <SettingsTabBar
+        activeTab="primary"
+        onTabChange={vi.fn()}
+        primaryLabel="Nano Banana"
+        fallbackLabel="Flux Dev"
+      />
+    );
+
+    const primaryTab = screen.getByText("Nano Banana");
+    const fallbackTab = screen.getByText("Flux Dev");
+
+    // Active tab should have bg-neutral-700 class
+    expect(primaryTab.className).toContain("bg-neutral-700");
+    expect(fallbackTab.className).not.toContain("bg-neutral-700");
+  });
+
+  it("calls onTabChange when clicking inactive tab", () => {
+    const onTabChange = vi.fn();
+    render(
+      <SettingsTabBar
+        activeTab="primary"
+        onTabChange={onTabChange}
+        primaryLabel="Nano Banana"
+        fallbackLabel="Flux Dev"
+      />
+    );
+
+    fireEvent.click(screen.getByText("Flux Dev"));
+    expect(onTabChange).toHaveBeenCalledWith("fallback");
+  });
+
+  it("does not call onTabChange when clicking active tab", () => {
+    const onTabChange = vi.fn();
+    render(
+      <SettingsTabBar
+        activeTab="primary"
+        onTabChange={onTabChange}
+        primaryLabel="Nano Banana"
+        fallbackLabel="Flux Dev"
+      />
+    );
+
+    fireEvent.click(screen.getByText("Nano Banana"));
+    expect(onTabChange).not.toHaveBeenCalled();
+  });
+});