feat: Implement AI response feedback UI and complete high-priority features

Frontend Features:
- Add MessageFeedback component with thumbs up/down buttons
- Positive feedback submits immediately with success toast
- Negative feedback opens dialog for optional text input
- Integrate feedback buttons on all AI assistant messages
- Add success Snackbar confirmation message
- Translation keys added to ai.json (feedback section)

Backend Features:
- Add POST /api/v1/ai/feedback endpoint
- Create FeedbackDto with conversation ID validation
- Implement submitFeedback service method
- Store feedback in conversation metadata with timestamps
- Add audit logging for feedback submissions
- Fix conversationId regex validation to support nanoid format

Legal & Compliance:
- Implement complete EULA acceptance flow with modal
- Create reusable legal content components (Terms, Privacy, EULA)
- Add LegalDocumentViewer for nested modal viewing
- Cookie Consent Banner with GDPR compliance
- Legal pages with AppShell navigation
- EULA acceptance tracking in user entity

Branding Updates:
- Rebrand from "Maternal App" to "ParentFlow"
- Update all icons (72px to 512px) from high-res source
- PWA manifest updated with ParentFlow branding
- Contact email: hello@parentflow.com
- Address: Serbota 3, Bucharest, Romania

Bug Fixes:
- Fix chat endpoint validation (support nanoid conversation IDs)
- Fix EULA acceptance API call (use apiClient vs hardcoded localhost)
- Fix icon loading errors with proper PNG generation

Documentation:
- Mark 11 high-priority features as complete in REMAINING_FEATURES.md
- Update feature statistics: 73/139 complete (53%)
- All high-priority features now complete! 🎉

Files Changed:
Frontend: 21 files (components, pages, locales, icons)
Backend: 6 files (controller, service, DTOs, migrations)
Docs: 1 file (REMAINING_FEATURES.md)

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

maternal-web/app/layout.tsx

@@ -11,6 +11,8 @@ import { FocusManagementProvider } from '@/components/providers/FocusManagementP
 import { BackgroundSyncProvider } from '@/components/providers/BackgroundSyncProvider';
 import { InstallPrompt } from '@/components/pwa/InstallPrompt';
 import { I18nProvider } from '@/components/providers/I18nProvider';
+import { EULACheck } from '@/components/legal/EULACheck';
+import { CookieConsent } from '@/components/common/banners/CookieConsent';
 // import { PerformanceMonitor } from '@/components/common/PerformanceMonitor'; // Temporarily disabled
 import './globals.css';
 
@@ -56,11 +58,13 @@ export default function RootLayout({
                       <FocusManagementProvider>
                         <SkipNavigation />
                         {/* <PerformanceMonitor /> */}
+                        <EULACheck />
                         <main id="main-content" tabIndex={-1}>
                           {children}
                         </main>
                         <VoiceFloatingButton />
                         <InstallPrompt />
+                        <CookieConsent />
                       </FocusManagementProvider>
                     </ThemeRegistry>
                   </BackgroundSyncProvider>