Implement AI chat history system with enhanced memory (Phases 1 & 2)

Phase 1 - Database Schema & Basic API:
- Add ChatConversation and ChatMessage tables with proper relationships
- Create conversation CRUD API endpoints with authentication
- Update chat API to support persistent conversations
- Implement auto-generated conversation titles and language separation
- Add conversation soft delete and user-specific access control

Phase 2 - Enhanced Memory System:
- Implement intelligent context selection beyond simple chronological order
- Add relevance scoring for older messages based on keyword overlap and biblical references
- Create automatic message summarization for very long conversations
- Optimize token usage with smart context management (1500 token budget)
- Add biblical awareness with Romanian/English book name detection
- Implement time-based relevance decay for better context prioritization

Frontend Improvements:
- Add chat history button to floating chat header
- Create basic history panel UI with placeholder content
- Maintain backward compatibility for anonymous users

Database Changes:
- Enhanced schema with conversation relationships and message roles
- Proper indexing for performance and user-specific queries
- Migration completed successfully with prisma db push

🤖 Generated with [Claude Code](https://claude.ai/code)

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

components/chat/floating-chat.tsx

@@ -30,9 +30,11 @@ import {
   ThumbDown,
   Minimize,
   Launch,
+  History,
 } from '@mui/icons-material'
 import { useState, useRef, useEffect } from 'react'
 import { useTranslations, useLocale } from 'next-intl'
+import ReactMarkdown from 'react-markdown'
 
 interface ChatMessage {
   id: string
@@ -48,6 +50,7 @@ export default function FloatingChat() {
   const [isOpen, setIsOpen] = useState(false)
   const [isMinimized, setIsMinimized] = useState(false)
   const [isFullscreen, setIsFullscreen] = useState(false)
+  const [showHistory, setShowHistory] = useState(false)
   const [messages, setMessages] = useState<ChatMessage[]>([
     {
       id: '1',
@@ -240,6 +243,14 @@ export default function FloatingChat() {
               </Box>
             </Box>
             <Box>
+              <IconButton
+                size="small"
+                onClick={() => setShowHistory(!showHistory)}
+                sx={{ color: 'white', mr: 0.5 }}
+                title="Chat History"
+              >
+                <History />
+              </IconButton>
               <IconButton
                 size="small"
                 onClick={minimizeChat}
@@ -265,6 +276,39 @@ export default function FloatingChat() {
           </Box>
 
           {!isMinimized && (
+            <>
+              {/* Chat History Panel */}
+              {showHistory && (
+                <Box sx={{
+                  p: 2,
+                  borderBottom: 1,
+                  borderColor: 'divider',
+                  bgcolor: 'grey.50',
+                  maxHeight: '300px',
+                  overflowY: 'auto'
+                }}>
+                  <Typography variant="h6" sx={{ mb: 2 }}>
+                    Chat History
+                  </Typography>
+                  <Box sx={{ display: 'flex', flexDirection: 'column', gap: 1 }}>
+                    <Typography variant="body2" color="text.secondary" textAlign="center" sx={{ py: 2 }}>
+                      📝 Chat history will appear here
+                    </Typography>
+                    <Typography variant="body2" color="text.secondary" textAlign="center">
+                      ✨ Sign in to save your conversations
+                    </Typography>
+                    <Button
+                      variant="outlined"
+                      size="small"
+                      sx={{ mt: 1 }}
+                      onClick={() => setShowHistory(false)}
+                    >
+                      Close History
+                    </Button>
+                  </Box>
+                </Box>
+              )}
+
             <>
               {/* Suggested Questions */}
               <Box sx={{ p: 2, borderBottom: 1, borderColor: 'divider' }}>
@@ -338,15 +382,62 @@ export default function FloatingChat() {
                           maxWidth: '100%',
                         }}
                       >
-                        <Typography
-                          variant="body2"
-                          sx={{
-                            whiteSpace: 'pre-wrap',
-                            lineHeight: 1.4,
-                          }}
-                        >
-                          {message.content}
-                        </Typography>
+                        {message.role === 'assistant' ? (
+                          <ReactMarkdown
+                            components={{
+                              p: ({ children }) => (
+                                <Typography
+                                  variant="body2"
+                                  sx={{ mb: 1, lineHeight: 1.4 }}
+                                >
+                                  {children}
+                                </Typography>
+                              ),
+                              h3: ({ children }) => (
+                                <Typography
+                                  variant="h6"
+                                  sx={{ fontWeight: 'bold', mt: 2, mb: 1 }}
+                                >
+                                  {children}
+                                </Typography>
+                              ),
+                              strong: ({ children }) => (
+                                <Typography
+                                  component="span"
+                                  sx={{ fontWeight: 'bold' }}
+                                >
+                                  {children}
+                                </Typography>
+                              ),
+                              ul: ({ children }) => (
+                                <Box component="ul" sx={{ pl: 2, mb: 1 }}>
+                                  {children}
+                                </Box>
+                              ),
+                              li: ({ children }) => (
+                                <Typography
+                                  component="li"
+                                  variant="body2"
+                                  sx={{ mb: 0.5 }}
+                                >
+                                  {children}
+                                </Typography>
+                              ),
+                            }}
+                          >
+                            {message.content}
+                          </ReactMarkdown>
+                        ) : (
+                          <Typography
+                            variant="body2"
+                            sx={{
+                              whiteSpace: 'pre-wrap',
+                              lineHeight: 1.4,
+                            }}
+                          >
+                            {message.content}
+                          </Typography>
+                        )}
 
                         {message.role === 'assistant' && (
                           <Box sx={{ display: 'flex', gap: 0.5, mt: 1, justifyContent: 'flex-end' }}>