fix(rtl): les textes centrs en persan s'affichaient du mauvais cote

- Word: sous w:bidi, w:jc est logique (left=dbut=droite visuelle,
  right=fin=gauche visuelle) ; forcer jc=right alignait donc les
  paragraphes a gauche et crasait le centrage hrit du style.
  Dsormais le RTL pose w:bidi et w:rtl sans jamais toucher w:jc,
  comme le fait Word lui-mme pour un document RTL.
- PowerPoint: algn n'est plus crit quand le paragraphe n'en dfinit
  pas, afin de respecter l'alignement hrit du masque (titres centrs) ;
  algn=l explicite reste converti en r (algn est visuel en DrawingML).
- tests: centrage par style Word prserv, aucun w:jic crit, algn
  absent non cras côté PowerPoint

tests/test_translators/test_rtl_layout.py

@@ -22,6 +22,7 @@ from pathlib import Path
 
 import pytest
 from docx import Document
+from docx.enum.style import WD_STYLE_TYPE
 from docx.enum.text import WD_ALIGN_PARAGRAPH
 from lxml import etree
 from openpyxl import Workbook, load_workbook
@@ -447,6 +448,46 @@ class TestWordRtlLayout:
             )
             assert marker in part_text, part_name
 
+    def test_fa_target_never_writes_alignment(self, tmp_path):
+        """Reported bug: centered Persian text rendered on the wrong side.
+
+        Under w:bidi, Word interprets w:jc logically: "right" means the
+        END of the line — the visual LEFT for RTL. Writing jc="right"
+        pushes unaligned paragraphs to the left and overrides style-level
+        centering. RTL must add w:bidi (+ run w:rtl) and never touch
+        w:jc: unaligned paragraphs start at the right edge, explicit
+        "left" resolves to the right edge, and centering stays centering.
+        """
+        provider = MockTranslationProvider(
+            {"Plain body": "FA1", "Styled centered title": "FA2"}
+        )
+        translator = WordTranslator(provider=provider)
+
+        doc = Document()
+        doc.add_paragraph("Plain body")  # no alignment anywhere
+        style = doc.styles.add_style("CenteredCustom", WD_STYLE_TYPE.PARAGRAPH)
+        style.paragraph_format.alignment = WD_ALIGN_PARAGRAPH.CENTER
+        doc.add_paragraph("Styled centered title", style=style)  # centered via style
+
+        input_file = tmp_path / "input.docx"
+        doc.save(input_file)
+        output_file = tmp_path / "output.docx"
+        translator.translate_file(input_file, output_file, "fa")
+
+        doc_out = Document(output_file)
+        for para in doc_out.paragraphs:
+            pPr = para._p.find(f"{{{W_NS}}}pPr")
+            assert pPr is not None
+            assert pPr.find(f"{{{W_NS}}}bidi") is not None
+            assert pPr.find(f"{{{W_NS}}}jc") is None, "RTL must never write w:jc"
+
+        # The style-level centering still resolves to centered
+        assert (
+            doc_out.paragraphs[1].style.paragraph_format.alignment
+            == WD_ALIGN_PARAGRAPH.CENTER
+        )
+        assert "FA2" in doc_out.paragraphs[1].text
+
     def test_fr_target_no_rtl_attributes(self, tmp_path):
         """A non-RTL target produces no bidi/bidiVisual/rtl markup."""
         provider = MockTranslationProvider({"Body text": "FR_Body"})
@@ -552,7 +593,14 @@ class TestPptxRtlLayout:
         assert pPr.get("rtl") == "1"
         assert pPr.get("algn") == "just", "justified alignment must be preserved"
 
-    def test_alignment_absent_becomes_right(self, tmp_path):
+    def test_alignment_absent_inherits_from_layout(self, tmp_path):
+        """Reported bug: centered Persian text rendered on the wrong side.
+
+        When algn is absent the paragraph inherits its alignment from
+        the layout/master (often centered titles); writing algn="r"
+        overrides that inheritance. rtl="1" alone already renders the
+        paragraph from its start edge (right), so algn stays untouched.
+        """
         provider = MockTranslationProvider({"Plain text": "AR_Plain"})
         translator = PowerPointTranslator(provider=provider)
         input_file = self._build_single_text_pptx(tmp_path, "Plain text")
@@ -564,7 +612,7 @@ class TestPptxRtlLayout:
         pPr = para._p.find(f"{{{A_NS}}}pPr")
         assert pPr is not None
         assert pPr.get("rtl") == "1"
-        assert pPr.get("algn") == "r"
+        assert pPr.get("algn") is None, "inherited alignment must not be overridden"
 
     def test_alignment_left_becomes_right(self, tmp_path):
         provider = MockTranslationProvider({"Left text": "AR_Left"})