fix: UTF-8 BOM in RDP bundle zip for Russian Windows PowerShell (0.20.16)

backend/app/services/rdp_bundle_delivery.py

@@ -10,6 +10,8 @@ from pathlib import Path
 from threading import Lock
 
 TTL_SECONDS = 600
+_UTF8_BOM = b"\xef\xbb\xbf"
+_BOM_SUFFIXES = {".ps1", ".txt"}
 
 _lock = Lock()
 _entries: dict[str, tuple[bytes, float]] = {}
@@ -21,13 +23,23 @@ def _prune_expired(now: float) -> None:
         _entries.pop(token, None)
 
 
+def _bundle_file_bytes(path: Path) -> bytes:
+    data = path.read_bytes()
+    if path.suffix.lower() in _BOM_SUFFIXES and not data.startswith(_UTF8_BOM):
+        return _UTF8_BOM + data
+    return data
+
+
 def build_rdp_bundle_zip(repo_dir: Path, filenames: tuple[str, ...]) -> bytes:
     buffer = io.BytesIO()
     with zipfile.ZipFile(buffer, "w", zipfile.ZIP_DEFLATED) as archive:
         for name in filenames:
             path = repo_dir / name
             if path.is_file():
-                archive.write(path, name)
+                info = zipfile.ZipInfo(name)
+                info.compress_type = zipfile.ZIP_DEFLATED
+                info.flag_bits |= 0x800
+                archive.writestr(info, _bundle_file_bytes(path))
     return buffer.getvalue()