Add comprehensive error handling to raw file API endpoint with permission checks, binary file fallback, and detailed logging for read operations

backend/main.py

@@ -411,7 +411,22 @@ async def api_file_raw(vault_name: str, path: str = Query(..., description="Rela
     if not file_path.exists() or not file_path.is_file():
         raise HTTPException(status_code=404, detail=f"File not found: {path}")
 
-    raw = file_path.read_text(encoding="utf-8", errors="replace")
+    try:
+        raw = file_path.read_text(encoding="utf-8", errors="replace")
+    except PermissionError as e:
+        logger.error(f"Permission denied reading raw file {path}: {e}")
+        raise HTTPException(status_code=403, detail=f"Permission denied: cannot read file {path}")
+    except UnicodeDecodeError:
+        # Binary file - try to read as binary and decode with errors='replace'
+        try:
+            raw = file_path.read_bytes().decode("utf-8", errors="replace")
+        except Exception as e:
+            logger.error(f"Error reading binary raw file {path}: {e}")
+            raise HTTPException(status_code=500, detail=f"Cannot read file: {str(e)}")
+    except Exception as e:
+        logger.error(f"Unexpected error reading raw file {path}: {e}")
+        raise HTTPException(status_code=500, detail=f"Error reading file: {str(e)}")
+    
     return {"vault": vault_name, "path": path, "raw": raw}