Add standalone GusVoice AWG bot and Linux installer

vendor/gusvoice_bot/errors.py

@@ -0,0 +1,24 @@
+# SPDX-License-Identifier: MIT
+"""Errors of the GusVoice Bot API client."""
+from __future__ import annotations
+
+from typing import Optional
+
+
+class GusVoiceError(Exception):
+    """Base class of every error raised by this package."""
+
+
+class GusVoiceApiError(GusVoiceError):
+    """The server answered `{"ok": false, ...}` (or a non-JSON error page).
+
+    `code` is `error_code` (or the HTTP status), `description` is the server text, `retry_after` (seconds) comes with 429.
+    """
+
+    def __init__(self, code: int, description: str, retry_after: Optional[int] = None, method: Optional[str] = None) -> None:
+        self.code = code
+        self.description = description
+        self.retry_after = retry_after
+        self.method = method
+        where = f"{method}: " if method else ""
+        super().__init__(f"{where}{code} {description}")