Phase 6: QA fixes for Lighthouse and navigation

- Map is a titled iframe (accessibility); drop @next/third-parties
- "Services" nav toggle is a real button with aria-expanded (SEO
  crawlable-anchors, accessibility)
- Hero images use default quality; page-header image is preloaded (LCP)
- Mobile services submenu no longer clips its last item

Mobile Lighthouse: / 94/100/100/100, /services/computer-repair
96/100/100/100, /areas/henderson 97/100/100/100, /contact 95/100/100/100
(performance/accessibility/best practices/SEO).

Co-Authored-By: Claude Opus 5.5 <[email protected]>

src/app/components/Navbar.js

@@ -87,13 +87,15 @@ export default function Navbar() {
               data-state={isDropdownActive ? "open" : "close"}
               className="flex items-center justify-center gap-1 [&[data-state=open]>svg]:rotate-180"
             >
-              <a
+              <button
+                type="button"
+                aria-expanded={isDropdownActive}
                 className={`${styles.dropdownTitle} 
-              ${pathname === "/services" ? styles.active : ""}`}
+              ${pathname.startsWith("/services") ? styles.active : ""}`}
                 onClick={handleDropdownToggle}
               >
                 Services
-              </a>
+              </button>
               <ChevronDownIcon className="text-muted-foreground pointer-events-none size-4 shrink-0 translate-y-0.5 transition-transform duration-200" />
             </div>
             <ul className={styles.dropdownMenu}>