fix(pitch): showcase sidebar shows only filtered slides + AI presenter via FAB

NavigationFAB and SlideOverview now accept slideNames prop and render only the
active slide list (filtered for showcase mode). Adds AI presenter start button
to the FAB footer so it's accessible even when intro-presenter slide is hidden.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

pitch-deck/components/NavigationFAB.tsx

@@ -13,6 +13,8 @@ interface NavigationFABProps {
   onGoToSlide: (index: number) => void
   lang: Language
   onToggleLanguage: () => void
+  slideNames?: string[]
+  onPresenterStart?: () => void
 }
 
 export default function NavigationFAB({
@@ -22,6 +24,8 @@ export default function NavigationFAB({
   onGoToSlide,
   lang,
   onToggleLanguage,
+  slideNames: slideNamesProp,
+  onPresenterStart,
 }: NavigationFABProps) {
   const [isOpen, setIsOpen] = useState(false)
   const [isFullscreen, setIsFullscreen] = useState(false)
@@ -35,6 +39,7 @@ export default function NavigationFAB({
     })
   }, [])
   const i = t(lang)
+  const activeSlideNames = slideNamesProp ?? i.slideNames
 
   const toggleFullscreen = useCallback(() => {
     if (!document.fullscreenElement) {
@@ -89,7 +94,7 @@ export default function NavigationFAB({
 
             {/* Slide List */}
             <div className="overflow-y-auto max-h-[55vh] py-2">
-              {i.slideNames.map((name, idx) => {
+              {activeSlideNames.map((name, idx) => {
                 const isActive = idx === currentIndex
                 const isVisited = visitedSlides.has(idx)
                 const isAI = idx === totalSlides - 1
@@ -164,6 +169,18 @@ export default function NavigationFAB({
                 </div>
               </button>
 
+              {/* AI Presenter */}
+              {onPresenterStart && (
+                <button
+                  onClick={() => { onPresenterStart(); setIsOpen(false) }}
+                  className="w-full flex items-center justify-between px-3 py-2 rounded-lg
+                    bg-indigo-500/10 hover:bg-indigo-500/20 transition-colors text-sm"
+                >
+                  <span className="text-indigo-300">{lang === 'de' ? 'KI-Präsentation starten' : 'Start AI Presenter'}</span>
+                  <Bot className="w-4 h-4 text-indigo-400" />
+                </button>
+              )}
+
               {/* Fullscreen */}
               <button
                 onClick={toggleFullscreen}