fix(pdf): corriger la mise en page et l'affichage des traductions en persan et RTL

- Prioriser les polices couvrant l'alphabet latin et arabo-persan (DejaVu Sans, Arial) afin d'eviter les debordements et caracteres manquants

- Decouper et mettre en miroir le texte ligne par ligne pour preserver l'ordre vertical de lecture du haut vers le bas

- Ignorer les fonds de diapositives pleine page pour eviter de tronconner les phrases sur fond colore

- Supporter les listes avec alinea pour fusionner les phrases longues sans coupure de mots

- Ajouter fonts-dejavu-core au conteneur Docker de production

translators/pdf_translator.py

@@ -96,6 +96,87 @@ def _shape_rtl(text: str) -> str:
         return text
 
 
+def _shape_rtl_multiline(
+    text: str,
+    max_width: float = 0.0,
+    fontsize: float = 12.0,
+    fontfile: Optional[str] = None,
+) -> str:
+    """Shape Arabic-script text line by line to preserve top-to-bottom reading.
+
+    When text spans multiple lines, applying get_display globally reverses the
+    entire paragraph, causing LTR engines (like PyMuPDF) to render lines
+    from bottom to top. By wrapping words into lines first according to max_width
+    and shaping each line individually, line 1 stays at the top and the final line
+    at the bottom.
+    """
+    if not text:
+        return text
+    try:
+        import arabic_reshaper
+        from bidi.algorithm import get_display
+    except Exception:
+        return _shape_rtl(text)
+
+    # If no width provided or width is invalid, shape each line of existing newlines
+    if max_width <= 0:
+        paragraphs = text.splitlines()
+        shaped_paras = []
+        for p in paragraphs:
+            if not p.strip():
+                shaped_paras.append(p)
+            else:
+                try:
+                    shaped_paras.append(get_display(arabic_reshaper.reshape(p)))
+                except Exception:
+                    shaped_paras.append(p)
+        return "\n".join(shaped_paras)
+
+    # Try to load font for measurement
+    measure_font = None
+    if fontfile:
+        try:
+            import fitz
+            measure_font = fitz.Font(fontfile=fontfile)
+        except Exception:
+            measure_font = None
+
+    shaped_result = []
+    for para in text.splitlines():
+        if not para.strip():
+            shaped_result.append("")
+            continue
+
+        words = para.split(" ")
+        lines = []
+        cur_words = []
+
+        if measure_font:
+            for w in words:
+                if not w:
+                    continue
+                cand = (" ".join(cur_words + [w])) if cur_words else w
+                if measure_font.text_length(cand, fontsize=fontsize) <= max_width or not cur_words:
+                    cur_words.append(w)
+                else:
+                    lines.append(" ".join(cur_words))
+                    cur_words = [w]
+            if cur_words:
+                lines.append(" ".join(cur_words))
+        else:
+            lines = [para]
+
+        shaped_lines = []
+        for l in lines:
+            try:
+                shaped_lines.append(get_display(arabic_reshaper.reshape(l)))
+            except Exception:
+                shaped_lines.append(l)
+        shaped_result.append("\n".join(shaped_lines))
+
+    return "\n".join(shaped_result)
+
+
 # Font path → reportlab font name, for RTL fonts registered in this
 # process. A fixed name would make two consecutive translations with
 # different fonts (e.g. Arabic then Hebrew) overwrite each other's
@@ -221,18 +302,19 @@ class PDFTranslator:
     ]
 
     # Arabic-script-capable fonts (ar, fa, ur, ps, ku, sd, ug, ckb),
-    # searched FIRST for those targets. Debian's fonts-noto package
-    # ships Noto Naskh Arabic and Noto Sans Arabic under
-    # /usr/share/fonts/truetype/noto/; on Windows, Arial covers the
-    # whole Arabic script.
+    # searched FIRST for those targets. Prioritize fonts covering BOTH
+    # Latin and Arabic scripts (DejaVuSans, Arial) with standard line heights,
+    # so English brands/words and tight slide bboxes render without overflow or tofu.
     _RTL_ARABIC_FONT_SEARCH_PATHS = [
-        "/usr/share/fonts/truetype/noto/NotoNaskhArabic-Regular.ttf",
-        "/usr/share/fonts/truetype/noto/NotoSansArabic-Regular.ttf",
-        "/usr/share/fonts/opentype/noto/NotoNaskhArabic-Regular.ttf",
-        "/usr/share/fonts/opentype/noto/NotoSansArabic-Regular.ttf",
-        "/app/fonts/NotoNaskhArabic-Regular.ttf",
-        "/app/fonts/NotoSansArabic-Regular.ttf",
+        "/usr/share/fonts/truetype/dejavu/DejaVuSans.ttf",
+        "/app/fonts/DejaVuSans.ttf",
         "C:/Windows/Fonts/arial.ttf",
+        "/usr/share/fonts/truetype/noto/NotoSansArabic-Regular.ttf",
+        "/usr/share/fonts/opentype/noto/NotoSansArabic-Regular.ttf",
+        "/app/fonts/NotoSansArabic-Regular.ttf",
+        "/usr/share/fonts/truetype/noto/NotoNaskhArabic-Regular.ttf",
+        "/usr/share/fonts/opentype/noto/NotoNaskhArabic-Regular.ttf",
+        "/app/fonts/NotoNaskhArabic-Regular.ttf",
     ]
 
     # Hebrew-script-capable fonts (he, yi), searched FIRST for those
@@ -733,12 +815,17 @@ class PDFTranslator:
         # "code block" or "callout" patterns and avoid merging their
         # constituent lines.
         drawing_rects: list = []
+        page_area = (page.rect.width * page.rect.height) if (page.rect.width and page.rect.height) else 1.0
         if hasattr(page, "get_drawings"):
             try:
                 for d in page.get_drawings():
                     r = d.get("rect")
                     if r is not None and d.get("fill") is not None:
-                        drawing_rects.append(fitz.Rect(r))
+                        dr = fitz.Rect(r)
+                        # Exclude full-page or card backgrounds (>= 35% of page area)
+                        # so that slide backgrounds do not break normal paragraphs into lines.
+                        if (dr.width * dr.height) / page_area < 0.35:
+                            drawing_rects.append(dr)
             except Exception:
                 pass
 
@@ -959,14 +1046,18 @@ class PDFTranslator:
         if vertical_gap < 0 or vertical_gap > line_height * 1.5:
             return False
 
-        # Similar horizontal position (within 15pt)
-        if abs(a_bbox[0] - b_bbox[0]) > 15:
+        # Horizontal alignment: left-aligned (within 15pt) OR hanging indent (line b indented up to 36pt)
+        x_diff = abs(a_bbox[0] - b_bbox[0])
+        is_hanging_indent = (0 <= b_bbox[0] - a_bbox[0] <= 36.0)
+        if x_diff > 15 and not is_hanging_indent:
             return False
 
-        # Don't merge if widths are very different (likely different columns)
+        # If b is shorter than a, it is typically the last line of the paragraph,
+        # provided it does not extend significantly past a's right edge.
+        # Only reject if b extends far past a's right margin.
         a_width = a_bbox[2] - a_bbox[0]
         b_width = b_bbox[2] - b_bbox[0]
-        if a_width > 0 and abs(b_width - a_width) / a_width > 0.5:
+        if b_bbox[2] > a_bbox[2] + 25 and b_width > a_width * 1.5:
             return False
 
         return True
@@ -1054,12 +1145,6 @@ class PDFTranslator:
 
         original_rect = fitz.Rect(block["bbox"])
         translated = block["translated"]
-        if rtl_target:
-            # Shape Arabic-script text (contextual letter forms + visual
-            # order) before insertion — insert_textbox does no bidi
-            # processing of its own. Missing/failed libs degrade to the
-            # raw text (warning logged inside _shape_rtl).
-            translated = _shape_rtl(translated)
         target_size = block["font_size"]
 
         color = self._int_to_rgb(block["color"])
@@ -1126,38 +1211,38 @@ class PDFTranslator:
 
         # Tier 0: original rect, original size
         # insert_textbox returns >= 0 if text fit, < 0 if overflow (in points)
-        rc = self._try_insert(page, original_rect, translated, target_size, fontname, fontfile, color, align)
+        rc = self._try_insert(page, original_rect, translated, target_size, fontname, fontfile, color, align, rtl_target=rtl_target)
         if rc is not None and rc >= 0:
             return True
 
         # Tier 1: expanded horizontal, original size
         if expanded_h.width > original_rect.width + 1:
-            rc = self._try_insert(page, expanded_h, translated, target_size, fontname, fontfile, color, align)
+            rc = self._try_insert(page, expanded_h, translated, target_size, fontname, fontfile, color, align, rtl_target=rtl_target)
             if rc is not None and rc >= 0:
                 return True
 
         # Tier 2: expanded vertical, original size
         if expanded_v.height > original_rect.height + 1:
-            rc = self._try_insert(page, expanded_v, translated, target_size, fontname, fontfile, color, align)
+            rc = self._try_insert(page, expanded_v, translated, target_size, fontname, fontfile, color, align, rtl_target=rtl_target)
             if rc is not None and rc >= 0:
                 return True
 
         # Tier 3: shrink once
         size_1 = max(target_size * FONT_SHRINK_FACTOR, min_size)
         if size_1 < target_size - 0.1:  # only try if shrink is meaningful
-            rc = self._try_insert(page, expanded_v, translated, size_1, fontname, fontfile, color, align)
+            rc = self._try_insert(page, expanded_v, translated, size_1, fontname, fontfile, color, align, rtl_target=rtl_target)
             if rc is not None and rc >= 0:
                 return True
 
         # Tier 4: shrink twice
         size_2 = max(target_size * FONT_SHRINK_FACTOR * FONT_SHRINK_FACTOR, min_size)
         if size_2 < size_1 - 0.1:
-            rc = self._try_insert(page, expanded_v, translated, size_2, fontname, fontfile, color, align)
+            rc = self._try_insert(page, expanded_v, translated, size_2, fontname, fontfile, color, align, rtl_target=rtl_target)
             if rc is not None and rc >= 0:
                 return True
 
         # Tier 5: hit the min size floor
-        rc = self._try_insert(page, expanded_v, translated, min_size, fontname, fontfile, color, align)
+        rc = self._try_insert(page, expanded_v, translated, min_size, fontname, fontfile, color, align, rtl_target=rtl_target)
         if rc is not None and rc >= 0:
             return True
 
@@ -1190,13 +1275,19 @@ class PDFTranslator:
             pass
 
     def _try_insert(
-        self, page, rect, text, fontsize, fontname, fontfile, color, align
+        self, page, rect, text, fontsize, fontname, fontfile, color, align, rtl_target: bool = False
     ):
         """Attempt insert_textbox, returns rc or None on error."""
         try:
+            if rtl_target and text:
+                text_to_insert = _shape_rtl_multiline(
+                    text, max_width=rect.width, fontsize=fontsize, fontfile=fontfile
+                )
+            else:
+                text_to_insert = text
             return page.insert_textbox(
                 rect,
-                text,
+                text_to_insert,
                 fontsize=fontsize,
                 fontname=fontname,
                 fontfile=fontfile,