refactor: #85 T9 extrait realtime et render vers modules dedies (comportement inchange)

backend/routers/files_media.py

@@ -9,7 +9,8 @@ d'authentification.
 
 Adaptations strictement équivalentes :
 - ``_resolve_safe_path`` → :mod:`backend.services.paths` (pass-through).
-- ``_render_markdown`` reste dans ``main`` (import différé).
+- ``_render_markdown`` vient de :mod:`backend.render` (#85 T9, sans cycle
+  d'import).
 - ``_resolve_export_target`` / ``_safe_export_name`` (export uniquement)
   sont définis ici ; ``stream_file_with_range`` vit dans
   :mod:`backend.routers.helpers` (partagé).
@@ -29,6 +30,7 @@ from backend.history import record_open
 from backend.indexer import get_vault_data, index, parse_markdown_file
 from backend.media_thumbs import generate_thumbnail, is_decodable
 from backend.media_types import is_audio, is_image, is_video, media_mime_type
+from backend.render import _render_markdown
 from backend.routers.helpers import media_max_inline_bytes, stream_file_with_range
 from backend.schemas import (
     AllVaultSettingsResponse,
@@ -85,8 +87,6 @@ def _safe_export_name(name: str) -> str:
 )
 async def api_file_pdf(vault_name: str, path: str = Query(..., description="Relative path to file"), current_user=Depends(require_auth)):
     """Download a markdown file as PDF."""
-    from backend.main import _render_markdown  # différé : évite l'import circulaire (#85)
-
     if generate_pdf is None:
         raise HTTPException(501, "PDF export unavailable (WeasyPrint/GTK not available)")
     if not check_vault_access(vault_name, current_user):