feat: affichage PDF avec TOC + frame-src CSP

- CSP: ajout frame-src 'self' http://127.0.0.1:* (permet iframe PDF)
- pdf_reader.py: extract_pdf_toc() — extrait les bookmarks/outline (pypdf + pymupdf)
- main.py: inclut pdf_toc dans la réponse /api/file pour les PDF
- viewer.js: sidebar TOC avec liens vers les pages (si bookmarks présents)
- style.css: layout .pdf-body flex + .pdf-toc sidebar 240px

backend/main.py

@@ -2339,9 +2339,10 @@ async def api_file(vault_name: str, path: str = Query(..., description="Relative
     # === PDF: special handling before read_text (binary file) ===
     if ext == ".pdf":
         try:
-            from backend.pdf_reader import extract_pdf_metadata, extract_pdf_text
+            from backend.pdf_reader import extract_pdf_metadata, extract_pdf_text, extract_pdf_toc
             pdf_text = extract_pdf_text(file_path, max_chars=100000)
             pdf_meta = extract_pdf_metadata(file_path)
+            pdf_toc = extract_pdf_toc(file_path)
             size = file_path.stat().st_size
             return {
                 "vault": vault_name,
@@ -2356,6 +2357,7 @@ async def api_file(vault_name: str, path: str = Query(..., description="Relative
                 "is_pdf": True,
                 "unsupported": False,
                 "pdf_metadata": pdf_meta,
+                "pdf_toc": pdf_toc,
                 "size_bytes": size,
             }
         except Exception as e:

backend/pdf_reader.py

@@ -57,6 +57,44 @@ def extract_pdf_metadata(file_path: Path) -> dict:
     return info
 
 
+def extract_pdf_toc(file_path: Path) -> list[dict]:
+    """Extract table of contents (bookmarks/outline) from a PDF file.
+    
+    Returns a list of {title, page, level} dicts, or empty list on failure.
+    """
+    toc: list[dict] = []
+    try:
+        if PDF_READER == "pymupdf":
+            doc = fitz.open(str(file_path))
+            raw = doc.get_toc(simple=False)
+            for item in raw:
+                toc.append({
+                    "title": str(item[1]),
+                    "page": item[2],
+                    "level": item[0],
+                })
+            doc.close()
+        elif PdfReader is not None:
+            reader = PdfReader(str(file_path))
+            outline = reader.outline
+            if outline:
+                def _flatten(items, level=1):
+                    for item in items:
+                        if isinstance(item, list):
+                            _flatten(item, level + 1)
+                        elif hasattr(item, 'title') and hasattr(item, 'page'):
+                            page_num = reader.get_page_number(item.page) + 1 if hasattr(item, 'page') and item.page else 1
+                            toc.append({
+                                "title": str(item.title),
+                                "page": page_num,
+                                "level": level,
+                            })
+                _flatten(outline)
+    except Exception as e:
+        logger.warning("Failed to extract PDF TOC from %s: %s", file_path, e)
+    return toc
+
+
 def _extract_pymupdf(file_path: Path, max_chars: int) -> str:
     doc = fitz.open(str(file_path))
     parts = []