feat(rtl): rendu droite-a-gauche complet pour Word, PowerPoint, Excel et PDF

- source unique RTL_LANGUAGES/is_rtl dans core/languages.py (fin des 3 copies)
- Word: bidi partout (corps, tableaux bidiVisual, notes/fin/commentaires,
  zones de texte, 6 zones d'en-tetes/pieds), insertion OOXML ordonnee,
  polices cs elargies aux 11 langues
- PowerPoint: alignements explicites preserves, notes du presentateur,
  indice de police <a:cs> insert a sa place
- Excel: feuilles affichees de droite a gauche, feuilles graphiques ignorees
- PDF: faconnage bidi (arabic-reshaper + python-bidi), polices par ecriture
  (arabe/hebreu), TTF enregistree pour le PDF recompose
- 46 tests nouveaux (tests/test_translators/test_rtl_layout.py), 253 au total

translators/excel_translator.py

@@ -23,6 +23,7 @@ from openpyxl.cell.cell import Cell
 from openpyxl.utils import get_column_letter
 
 from services.providers.base import TranslationProvider
+from core.languages import is_rtl
 
 
 from core.logging import get_logger
@@ -354,6 +355,26 @@ class ExcelTranslator:
                     except Exception as e:
                         _log_error("excel_sheet_images_failed", sheet_name=sheet_name, error=str(e))
 
+            # RTL targets: flip the sheet view so every sheet reads
+            # right-to-left (column A renders rightmost). Content and
+            # formatting are untouched — only the reading direction.
+            # Chartsheets have no `sheet_view` and must never break the
+            # save: each sheet is guarded individually.
+            if is_rtl(target_language):
+                flipped = 0
+                for sheet_name in workbook.sheetnames:
+                    ws = workbook[sheet_name]
+                    try:
+                        if getattr(ws, "sheet_view", None) is not None:
+                            ws.sheet_view.rightToLeft = True
+                            flipped += 1
+                    except Exception as e:
+                        _log_error(
+                            "excel_rtl_view_failed", sheet=sheet_name, error=str(e)
+                        )
+                if flipped:
+                    _log_info("excel_rtl_view_applied", sheets=flipped)
+
             try:
                 workbook.save(output_path)
             except Exception as e:
@@ -580,7 +601,14 @@ class ExcelTranslator:
     ) -> None:
         """Collect all translatable text from worksheet cells, cell comments,
         and cell hyperlinks (URLs are preserved as-is, but their display
-        labels are translated)."""
+        labels are translated).
+
+        Chartsheets are skipped: they have no cell grid (no iter_rows)
+        — their text lives in the chart XML, collected separately from
+        the ZIP.
+        """
+        if not hasattr(worksheet, "iter_rows"):
+            return
         for row in worksheet.iter_rows():
             for cell in row:
                 if cell.value is not None: