Commented terminal files

app/apps/keys/utils.py

@@ -9,6 +9,7 @@ _SANITIZE_RE = re.compile(r"[^a-z0-9_-]")
 
 
 def render_system_username(username: str, user_id: int) -> str:
+    # Render from template and then sanitize to an OS-safe username.
     template = settings.KEYWARDEN_ACCOUNT_USERNAME_TEMPLATE
     raw = template.replace("{{username}}", username or "")
     raw = raw.replace("{{user_id}}", str(user_id))
@@ -17,13 +18,16 @@ def render_system_username(username: str, user_id: int) -> str:
         cleaned = cleaned[:MAX_USERNAME_LEN]
     if cleaned:
         return cleaned
+    # Fall back to a deterministic, non-empty username.
     return f"kw_{user_id}"
 
 
 def sanitize_username(raw: str) -> str:
+    # Normalize to lowercase and replace disallowed characters.
     raw = (raw or "").lower()
     raw = _SANITIZE_RE.sub("_", raw)
     raw = raw.strip("-_")
     if raw.startswith("-"):
+        # Avoid leading dash, which can be interpreted as a CLI flag.
         return "kw" + raw
     return raw