feat(frontend): implement SectionAnchorTabs for improved navigation

- Replaced the existing navigation in PromptEditor and PanelAnchorNavigation with the new SectionAnchorTabs component for better code reuse and consistency.
- The SectionAnchorTabs component provides a shared interface for section navigation with equal-width columns and an active state indicator.

frontend/src/components/workflow/panels/PanelAnchorNavigation.tsx

@@ -3,6 +3,8 @@
 import type { ReactNode } from "react";
 import { useEffect, useRef, useState } from "react";
 
+import { SectionAnchorTabs } from "@/components/editor/section-anchor-tabs";
+
 export type PanelAnchorSection = {
   id: string;
   label: string;
@@ -128,33 +130,13 @@ export function PanelAnchorNavigation({
   return (
     <div className="flex min-h-0 flex-1 flex-col bg-canvas-soft">
       {sections.length > 1 && (
-        <nav
-          aria-label={ariaLabel}
-          className="shrink-0 overflow-x-auto overscroll-none border-b border-hairline bg-card px-4"
-        >
-          <div className="flex min-w-max">
-            {sections.map((section) => {
-              const active = resolvedActiveSection === section.id;
-
-              return (
-                <button
-                  key={section.id}
-                  type="button"
-                  aria-current={active ? "location" : undefined}
-                  onClick={() => scrollToSection(section.id)}
-                  className={[
-                    "-mb-px min-w-24 whitespace-nowrap border-b-2 px-3 py-2.5 text-center text-xs transition-colors",
-                    active
-                      ? "border-primary text-foreground"
-                      : "border-transparent text-muted-foreground hover:bg-surface-strong/50 hover:text-foreground",
-                  ].join(" ")}
-                >
-                  {section.label}
-                </button>
-              );
-            })}
-          </div>
-        </nav>
+        <SectionAnchorTabs
+          ariaLabel={ariaLabel}
+          sections={sections}
+          activeSectionId={resolvedActiveSection}
+          onSelect={scrollToSection}
+          className="bg-card px-4"
+        />
       )}
 
       <div