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

tests/test_translators/test_b3_5_pdf_smart_fit.py

@@ -99,7 +99,7 @@ class TestSmartFitTiers:
 
         translator = pdf_mod.PDFTranslator()
         result = translator._write_translated_block(
-            page, block, font_path=None, is_rtl=False
+            page, block, font_path=None, rtl_target=False
         )
         # Should have succeeded
         assert result is True
@@ -122,7 +122,7 @@ class TestSmartFitTiers:
         block = self._make_block(font_size=12, x0=100, y0=100, x1=400, y1=120)
         translator = pdf_mod.PDFTranslator()
         result = translator._write_translated_block(
-            page, block, font_path=None, is_rtl=False
+            page, block, font_path=None, rtl_target=False
         )
         assert result is True
         # Should have tried multiple times
@@ -137,7 +137,7 @@ class TestSmartFitTiers:
         block = self._make_block(font_size=20, x0=100, y0=100, x1=400, y1=120)
         translator = pdf_mod.PDFTranslator()
         result = translator._write_translated_block(
-            page, block, font_path=None, is_rtl=False
+            page, block, font_path=None, rtl_target=False
         )
         # Should have failed (returned False) because persistent overflow
         assert result is False
@@ -159,7 +159,7 @@ class TestSmartFitTiers:
         block = self._make_block(font_size=22, text="X" * 1000)
         translator = pdf_mod.PDFTranslator()
         translator._write_translated_block(
-            page, block, font_path=None, is_rtl=False
+            page, block, font_path=None, rtl_target=False
         )
         # All attempted sizes should be >= 22 * 0.90 = 19.8
         for s in call_sizes:
@@ -180,7 +180,7 @@ class TestSmartFitTiers:
         block = self._make_block(font_size=12, text="Y" * 1000)
         translator = pdf_mod.PDFTranslator()
         translator._write_translated_block(
-            page, block, font_path=None, is_rtl=False
+            page, block, font_path=None, rtl_target=False
         )
         for s in call_sizes:
             if s is not None:
@@ -201,7 +201,7 @@ class TestSmartFitTiers:
         with patch.object(pdf_mod, "_record_format_loss_metric", fake_record):
             block = self._make_block(font_size=12, text="Z" * 1000)
             result = translator._write_translated_block(
-                page, block, font_path=None, is_rtl=False
+                page, block, font_path=None, rtl_target=False
             )
         assert result is False
         # A format_loss metric should have been emitted
@@ -221,7 +221,7 @@ class TestSmartFitTiers:
         with patch.object(pdf_mod, "_record_format_loss_metric", fake_record):
             block = self._make_block(font_size=12, text="Short")
             result = translator._write_translated_block(
-                page, block, font_path=None, is_rtl=False
+                page, block, font_path=None, rtl_target=False
             )
         assert result is True
         # No format_loss should have been emitted
@@ -242,7 +242,7 @@ class TestSmartFitTiers:
         block = self._make_block(font_size=3, text="Q" * 1000)
         translator = pdf_mod.PDFTranslator()
         translator._write_translated_block(
-            page, block, font_path=None, is_rtl=False
+            page, block, font_path=None, rtl_target=False
         )
         # Exclude the placeholder font (used in graceful failure)
         real_sizes = [s for s in call_sizes if s is not None and s >= 4.5]