Ajout des fonctionnalités d'export Word et PDF pour le chat RAG

- Ajout de python-docx et reportlab aux dépendances
- Création du module utils/word_exporter.py pour l'export Word
- Création du module utils/pdf_exporter.py pour l'export PDF
- Ajout des routes /chat/export-word et /chat/export-pdf dans flask_app.py
- Ajout des boutons d'export (Word et PDF) dans chat.html
- Les boutons apparaissent après chaque réponse de l'assistant
- Support des questions reformulées avec question originale

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

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

generations/library_rag/utils/word_exporter.py

@@ -0,0 +1,144 @@
+"""Generate Word documents from chat exchanges.
+
+This module provides functionality to export chat conversations between users
+and the RAG assistant into formatted Microsoft Word documents (.docx).
+
+Example:
+    Export a simple chat exchange::
+
+        from pathlib import Path
+        from utils.word_exporter import create_chat_export
+
+        filepath = create_chat_export(
+            user_question="What is phenomenology?",
+            assistant_response="Phenomenology is a philosophical movement...",
+            output_dir=Path("output")
+        )
+
+    Export with reformulated question::
+
+        filepath = create_chat_export(
+            user_question="What does Husserl mean by phenomenology?",
+            assistant_response="Husserl defines phenomenology as...",
+            is_reformulated=True,
+            original_question="What is phenomenology?",
+            output_dir=Path("output")
+        )
+"""
+
+from pathlib import Path
+from typing import Optional
+from datetime import datetime
+
+try:
+    from docx import Document
+    from docx.shared import Pt, RGBColor, Inches
+    from docx.enum.text import WD_PARAGRAPH_ALIGNMENT
+except ImportError:
+    raise ImportError(
+        "python-docx is required for Word export. "
+        "Install with: pip install python-docx"
+    )
+
+
+def create_chat_export(
+    user_question: str,
+    assistant_response: str,
+    is_reformulated: bool = False,
+    original_question: Optional[str] = None,
+    output_dir: Path = Path("output"),
+) -> Path:
+    """Create a Word document from a chat exchange.
+
+    Args:
+        user_question: The user's question (or reformulated version).
+        assistant_response: The assistant's complete response text.
+        is_reformulated: Whether the question was reformulated by the system.
+            If True, both original and reformulated questions are included.
+        original_question: The original user question before reformulation.
+            Only used when is_reformulated is True.
+        output_dir: Directory where the .docx file will be saved.
+            Created if it doesn't exist.
+
+    Returns:
+        Path to the generated .docx file.
+
+    Raises:
+        OSError: If the output directory cannot be created or file cannot be saved.
+
+    Example:
+        >>> from pathlib import Path
+        >>> filepath = create_chat_export(
+        ...     user_question="Qu'est-ce que la phénoménologie ?",
+        ...     assistant_response="La phénoménologie est...",
+        ...     output_dir=Path("output")
+        ... )
+        >>> print(filepath)
+        output/chat_export_20250101_123045.docx
+    """
+    # Create document
+    doc = Document()
+
+    # Set margins to 1 inch on all sides
+    sections = doc.sections
+    for section in sections:
+        section.top_margin = Inches(1)
+        section.bottom_margin = Inches(1)
+        section.left_margin = Inches(1)
+        section.right_margin = Inches(1)
+
+    # Title
+    title = doc.add_heading("Conversation RAG - Export", level=1)
+    title.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
+
+    # Date
+    date_p = doc.add_paragraph()
+    date_p.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
+    date_run = date_p.add_run(
+        f"Exporté le {datetime.now().strftime('%d/%m/%Y à %H:%M')}"
+    )
+    date_run.font.size = Pt(10)
+    date_run.font.color.rgb = RGBColor(128, 128, 128)
+
+    doc.add_paragraph()  # Spacer
+
+    # Original question (if reformulated)
+    if is_reformulated and original_question:
+        doc.add_heading("Question Originale", level=2)
+        original_p = doc.add_paragraph(original_question)
+        original_p.style = "Intense Quote"
+        doc.add_paragraph()
+
+    # User question
+    question_label = "Question Reformulée" if is_reformulated else "Question"
+    doc.add_heading(question_label, level=2)
+    question_p = doc.add_paragraph(user_question)
+    question_p.style = "Intense Quote"
+
+    doc.add_paragraph()  # Spacer
+
+    # Assistant response
+    doc.add_heading("Réponse de l'Assistant", level=2)
+    response_p = doc.add_paragraph(assistant_response)
+
+    # Footer
+    doc.add_paragraph()
+    footer_p = doc.add_paragraph()
+    footer_p.alignment = WD_PARAGRAPH_ALIGNMENT.CENTER
+    footer_run = footer_p.add_run(
+        "Généré par Library RAG - Recherche Philosophique"
+    )
+    footer_run.font.size = Pt(9)
+    footer_run.font.color.rgb = RGBColor(150, 150, 150)
+    footer_run.italic = True
+
+    # Generate filename with timestamp
+    timestamp = datetime.now().strftime("%Y%m%d_%H%M%S")
+    filename = f"chat_export_{timestamp}.docx"
+    filepath = output_dir / filename
+
+    # Save document (create directory if needed)
+    output_dir.mkdir(parents=True, exist_ok=True)
+    doc.save(str(filepath))
+
+    return filepath