feat(pitch-deck): add AI Presenter mode with LiteLLM migration and FAQ system

- Migrate chat API from Ollama to LiteLLM (OpenAI-compatible SSE)
- Add 15-min presenter storyline with bilingual scripts for all 20 slides
- Add FAQ system (30 entries) with keyword matching for instant answers
- Add IntroPresenterSlide with avatar placeholder and start button
- Add PresenterOverlay (progress bar, subtitle text, play/pause/stop)
- Add AvatarPlaceholder with pulse animation during speaking
- Add usePresenterMode hook (state machine: idle→presenting→paused→answering→resuming)
- Add 'P' keyboard shortcut to toggle presenter mode
- Support [GOTO:slide-id] markers in chat responses
- Dynamic slide count (was hardcoded 13, now from SLIDE_ORDER)
- TTS stub prepared for future Piper integration

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

pitch-deck/components/PitchDeck.tsx

@@ -5,6 +5,7 @@ import { AnimatePresence } from 'framer-motion'
 import { useSlideNavigation } from '@/lib/hooks/useSlideNavigation'
 import { useKeyboard } from '@/lib/hooks/useKeyboard'
 import { usePitchData } from '@/lib/hooks/usePitchData'
+import { usePresenterMode } from '@/lib/hooks/usePresenterMode'
 import { Language, PitchData } from '@/lib/types'
 
 import ParticleBackground from './ParticleBackground'
@@ -14,7 +15,10 @@ import NavigationFAB from './NavigationFAB'
 import ChatFAB from './ChatFAB'
 import SlideOverview from './SlideOverview'
 import SlideContainer from './SlideContainer'
+import PresenterOverlay from './presenter/PresenterOverlay'
+import AvatarPlaceholder from './presenter/AvatarPlaceholder'
 
+import IntroPresenterSlide from './slides/IntroPresenterSlide'
 import CoverSlide from './slides/CoverSlide'
 import ProblemSlide from './slides/ProblemSlide'
 import SolutionSlide from './slides/SolutionSlide'
@@ -45,6 +49,13 @@ export default function PitchDeck({ lang, onToggleLanguage }: PitchDeckProps) {
   const nav = useSlideNavigation()
   const [fabOpen, setFabOpen] = useState(false)
 
+  const presenter = usePresenterMode({
+    goToSlide: nav.goToSlide,
+    currentSlide: nav.currentIndex,
+    totalSlides: nav.totalSlides,
+    language: lang,
+  })
+
   const toggleFullscreen = useCallback(() => {
     if (!document.fullscreenElement) {
       document.documentElement.requestFullscreen()
@@ -66,6 +77,7 @@ export default function PitchDeck({ lang, onToggleLanguage }: PitchDeckProps) {
     onFullscreen: toggleFullscreen,
     onLanguageToggle: onToggleLanguage,
     onMenuToggle: toggleMenu,
+    onPresenterToggle: presenter.toggle,
     onGoToSlide: nav.goToSlide,
     enabled: !nav.showOverview,
   })
@@ -96,6 +108,14 @@ export default function PitchDeck({ lang, onToggleLanguage }: PitchDeckProps) {
     if (!data) return null
 
     switch (nav.currentSlide) {
+      case 'intro-presenter':
+        return (
+          <IntroPresenterSlide
+            lang={lang}
+            onStartPresenter={presenter.start}
+            isPresenting={presenter.state !== 'idle'}
+          />
+        )
       case 'cover':
         return <CoverSlide lang={lang} onNext={nav.nextSlide} funding={data.funding} />
       case 'problem':
@@ -163,6 +183,8 @@ export default function PitchDeck({ lang, onToggleLanguage }: PitchDeckProps) {
         currentIndex={nav.currentIndex}
         visitedSlides={nav.visitedSlides}
         onGoToSlide={nav.goToSlide}
+        presenterState={presenter.state}
+        onPresenterInterrupt={presenter.pause}
       />
 
       <NavigationFAB
@@ -174,6 +196,21 @@ export default function PitchDeck({ lang, onToggleLanguage }: PitchDeckProps) {
         onToggleLanguage={onToggleLanguage}
       />
 
+      {/* Presenter UI */}
+      <AvatarPlaceholder state={presenter.state} />
+      <PresenterOverlay
+        state={presenter.state}
+        currentIndex={nav.currentIndex}
+        totalSlides={nav.totalSlides}
+        progress={presenter.progress}
+        displayText={presenter.displayText}
+        lang={lang}
+        onPause={presenter.pause}
+        onResume={presenter.resume}
+        onStop={presenter.stop}
+        onSkip={presenter.skipSlide}
+      />
+
       <AnimatePresence>
         {nav.showOverview && (
           <SlideOverview