fix: prevent exception diagnostics from leaking in API problem responses (#1405)

* Potential fix for code scanning alert no. 11: Information exposure through an exception

traceback should not be in client side code

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

* fix: keep unexpected API error details private and test problem responses

---------

Co-authored-by: Copilot Autofix powered by AI <62310815+github-advanced-security[bot]@users.noreply.github.com>

src/akkudoktoreos/server/rest/error.py

@@ -1,5 +1,4 @@
 import html
-import traceback
 from dataclasses import dataclass
 from typing import Optional, cast
 
@@ -8,8 +7,6 @@ from fastapi.exceptions import HTTPException, RequestValidationError
 from fastapi.responses import JSONResponse
 from loguru import logger
 
-from akkudoktoreos.core.coreabc import get_config
-
 
 @dataclass(slots=True)
 class EOSProblem(Exception):
@@ -45,9 +42,6 @@ def _problem_response(
     if cause is not None:
         logger.exception(cause)
 
-        if get_config().logging.api_level in ("TRACE", "DEBUG"):
-            body["traceback"] = traceback.format_exception(cause)
-
     return JSONResponse(
         status_code=status,
         media_type="application/problem+json",
@@ -86,7 +80,7 @@ async def unexpected_exception_handler(request: Request, exc: Exception) -> JSON
         request=request,
         status=500,
         title="Internal Server Error",
-        detail=str(exc),
+        detail="An unexpected error occurred.",
         cause=exc,
         type="/problems/internal-server-error",
     )