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/components/features/ai-chat/MessageFeedback.tsx

@@ -0,0 +1,193 @@
+'use client';
+
+import { useState } from 'react';
+import {
+  Box,
+  IconButton,
+  Dialog,
+  DialogTitle,
+  DialogContent,
+  DialogActions,
+  Button,
+  TextField,
+  Typography,
+  Tooltip,
+  Snackbar,
+  Alert,
+} from '@mui/material';
+import { ThumbUp, ThumbDown, ThumbUpOutlined, ThumbDownOutlined } from '@mui/icons-material';
+import { useTranslation } from '@/hooks/useTranslation';
+import apiClient from '@/lib/api/client';
+
+interface MessageFeedbackProps {
+  messageId: string;
+  conversationId: string | null;
+}
+
+export function MessageFeedback({ messageId, conversationId }: MessageFeedbackProps) {
+  const { t } = useTranslation('ai');
+  const [feedbackType, setFeedbackType] = useState<'positive' | 'negative' | null>(null);
+  const [dialogOpen, setDialogOpen] = useState(false);
+  const [feedbackText, setFeedbackText] = useState('');
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const [snackbarOpen, setSnackbarOpen] = useState(false);
+
+  const handleFeedback = async (type: 'positive' | 'negative') => {
+    // If already submitted this type, ignore
+    if (feedbackType === type) return;
+
+    setFeedbackType(type);
+
+    // For negative feedback, open dialog for additional comments
+    if (type === 'negative') {
+      setDialogOpen(true);
+      return;
+    }
+
+    // For positive feedback, submit immediately
+    await submitFeedback(type, '');
+  };
+
+  const submitFeedback = async (type: 'positive' | 'negative', text: string) => {
+    if (!conversationId) return;
+
+    setIsSubmitting(true);
+    try {
+      await apiClient.post('/api/v1/ai/feedback', {
+        conversationId,
+        messageId,
+        feedbackType: type,
+        feedbackText: text || undefined,
+      });
+
+      console.log(`✅ Feedback submitted: ${type}`);
+
+      // Show success snackbar
+      setSnackbarOpen(true);
+
+      // Close dialog if open
+      if (dialogOpen) {
+        setDialogOpen(false);
+        setFeedbackText('');
+      }
+    } catch (error) {
+      console.error('Failed to submit feedback:', error);
+      // Reset feedback type on error
+      setFeedbackType(null);
+    } finally {
+      setIsSubmitting(false);
+    }
+  };
+
+  const handleDialogSubmit = async () => {
+    if (feedbackType) {
+      await submitFeedback(feedbackType, feedbackText);
+    }
+  };
+
+  const handleDialogClose = () => {
+    setDialogOpen(false);
+    setFeedbackText('');
+    // Reset feedback type if closing without submitting
+    if (!feedbackType || feedbackType === 'negative') {
+      setFeedbackType(null);
+    }
+  };
+
+  return (
+    <>
+      <Box sx={{ display: 'flex', gap: 0.5, mt: 1 }}>
+        <Tooltip title={t('feedback.helpful') || 'Helpful'}>
+          <IconButton
+            size="small"
+            onClick={() => handleFeedback('positive')}
+            disabled={isSubmitting}
+            sx={{
+              color: feedbackType === 'positive' ? 'success.main' : 'text.secondary',
+              '&:hover': { color: 'success.main' },
+            }}
+          >
+            {feedbackType === 'positive' ? (
+              <ThumbUp fontSize="small" />
+            ) : (
+              <ThumbUpOutlined fontSize="small" />
+            )}
+          </IconButton>
+        </Tooltip>
+
+        <Tooltip title={t('feedback.notHelpful') || 'Not helpful'}>
+          <IconButton
+            size="small"
+            onClick={() => handleFeedback('negative')}
+            disabled={isSubmitting}
+            sx={{
+              color: feedbackType === 'negative' ? 'error.main' : 'text.secondary',
+              '&:hover': { color: 'error.main' },
+            }}
+          >
+            {feedbackType === 'negative' ? (
+              <ThumbDown fontSize="small" />
+            ) : (
+              <ThumbDownOutlined fontSize="small" />
+            )}
+          </IconButton>
+        </Tooltip>
+      </Box>
+
+      {/* Feedback Dialog for negative feedback */}
+      <Dialog
+        open={dialogOpen}
+        onClose={handleDialogClose}
+        maxWidth="sm"
+        fullWidth
+      >
+        <DialogTitle>
+          {t('feedback.dialogTitle') || 'Help us improve'}
+        </DialogTitle>
+        <DialogContent>
+          <Typography variant="body2" color="text.secondary" sx={{ mb: 2 }}>
+            {t('feedback.dialogMessage') || 'What could have been better about this response?'}
+          </Typography>
+          <TextField
+            autoFocus
+            multiline
+            rows={4}
+            fullWidth
+            placeholder={t('feedback.placeholder') || 'Your feedback (optional)'}
+            value={feedbackText}
+            onChange={(e) => setFeedbackText(e.target.value)}
+            variant="outlined"
+          />
+        </DialogContent>
+        <DialogActions>
+          <Button onClick={handleDialogClose}>
+            {t('feedback.cancel') || 'Cancel'}
+          </Button>
+          <Button
+            onClick={handleDialogSubmit}
+            variant="contained"
+            disabled={isSubmitting}
+          >
+            {t('feedback.submit') || 'Submit'}
+          </Button>
+        </DialogActions>
+      </Dialog>
+
+      {/* Success Snackbar */}
+      <Snackbar
+        open={snackbarOpen}
+        autoHideDuration={3000}
+        onClose={() => setSnackbarOpen(false)}
+        anchorOrigin={{ vertical: 'bottom', horizontal: 'center' }}
+      >
+        <Alert
+          onClose={() => setSnackbarOpen(false)}
+          severity="success"
+          sx={{ width: '100%' }}
+        >
+          {t('feedback.thankYou') || 'Thank you for your feedback!'}
+        </Alert>
+      </Snackbar>
+    </>
+  );
+}