Move config file exceptions into app.exceptions

Move ConfigDirError, ConfigFileNotFoundError, ConfigFileExistsError, ConfigFileWriteError, and ConfigFileNameError from raw_config_io_service into the shared domain exception module. Update router and tests to import the exceptions from app.exceptions.

Docs/Refactoring.md

@@ -7,4 +7,5 @@ This document catalogues architecture violations, code smells, and structural is
 ## Completed Refactors
 
 - Moved `Fail2BanConnectionError` and `Fail2BanProtocolError` from `backend/app/utils/fail2ban_client.py` into `backend/app/exceptions.py`. Updated all router, service, and test call sites to import these domain exceptions from `app.exceptions` and retained backward compatibility through re-exporting in `app.utils.fail2ban_client`.
+- Moved config file exceptions (`ConfigDirError`, `ConfigFileNotFoundError`, `ConfigFileExistsError`, `ConfigFileWriteError`, `ConfigFileNameError`) from `backend/app/services/raw_config_io_service.py` into `backend/app/exceptions.py`. Updated router and tests to import the shared domain exceptions from `app.exceptions`.
 

Docs/Tasks.md

@@ -44,6 +44,8 @@ Reference: `Docs/Refactoring.md` for full analysis of each issue.
 
 **Why this is needed:** Routers should not reach into service internals to import exception types. All domain exceptions belong in the central registry so `main.py` global handlers and any future middleware can catch them uniformly.
 
+**Status:** Completed ✅
+
 ---
 
 ### Task 3 — Eliminate the `config_file_service.py` delegation façade

backend/app/exceptions.py

@@ -23,6 +23,44 @@ class ConfigOperationError(Exception):
     """Raised when a config payload update or command fails."""
 
 
+class ConfigDirError(Exception):
+    """Raised when the fail2ban config directory is missing or inaccessible."""
+
+
+class ConfigFileNotFoundError(Exception):
+    """Raised when a requested config file does not exist."""
+
+    def __init__(self, filename: str) -> None:
+        """Initialize with the filename that was not found.
+
+        Args:
+            filename: The filename that could not be located.
+        """
+        self.filename = filename
+        super().__init__(f"Config file not found: {filename!r}")
+
+
+class ConfigFileExistsError(Exception):
+    """Raised when trying to create a file that already exists."""
+
+    def __init__(self, filename: str) -> None:
+        """Initialize with the filename that already exists.
+
+        Args:
+            filename: The filename that conflicts.
+        """
+        self.filename = filename
+        super().__init__(f"Config file already exists: {filename!r}")
+
+
+class ConfigFileWriteError(Exception):
+    """Raised when a file cannot be written (permissions, disk full, etc.)."""
+
+
+class ConfigFileNameError(Exception):
+    """Raised when a supplied filename is invalid or unsafe."""
+
+
 class ServerOperationError(Exception):
     """Raised when a server control command (e.g. refresh) fails."""
 

backend/app/routers/file_config.py

@@ -52,7 +52,7 @@ from app.models.file_config import (
     JailConfigFilesResponse,
 )
 from app.services import raw_config_io_service
-from app.services.raw_config_io_service import (
+from app.exceptions import (
     ConfigDirError,
     ConfigFileExistsError,
     ConfigFileNameError,

backend/app/services/raw_config_io_service.py

@@ -17,6 +17,13 @@ from __future__ import annotations
 
 import asyncio
 from app.utils.async_utils import run_blocking
+from app.exceptions import (
+    ConfigDirError,
+    ConfigFileExistsError,
+    ConfigFileNameError,
+    ConfigFileNotFoundError,
+    ConfigFileWriteError,
+)
 import configparser
 import re
 from pathlib import Path
@@ -63,44 +70,6 @@ _SAFE_NAME_RE: re.Pattern[str] = re.compile(r"^[A-Za-z0-9][A-Za-z0-9._-]{0,127}$
 # ---------------------------------------------------------------------------
 
 
-class ConfigDirError(Exception):
-    """Raised when the fail2ban config directory is missing or inaccessible."""
-
-
-class ConfigFileNotFoundError(Exception):
-    """Raised when a requested config file does not exist."""
-
-    def __init__(self, filename: str) -> None:
-        """Initialise with the filename that was not found.
-
-        Args:
-            filename: The filename that could not be located.
-        """
-        self.filename = filename
-        super().__init__(f"Config file not found: {filename!r}")
-
-
-class ConfigFileExistsError(Exception):
-    """Raised when trying to create a file that already exists."""
-
-    def __init__(self, filename: str) -> None:
-        """Initialise with the filename that already exists.
-
-        Args:
-            filename: The filename that conflicts.
-        """
-        self.filename = filename
-        super().__init__(f"Config file already exists: {filename!r}")
-
-
-class ConfigFileWriteError(Exception):
-    """Raised when a file cannot be written (permissions, disk full, etc.)."""
-
-
-class ConfigFileNameError(Exception):
-    """Raised when a supplied filename is invalid or unsafe."""
-
-
 # ---------------------------------------------------------------------------
 # Internal path helpers
 # ---------------------------------------------------------------------------

backend/tests/test_routers/test_file_config.py

@@ -26,7 +26,7 @@ from app.models.file_config import (
     JailConfigFileContent,
     JailConfigFilesResponse,
 )
-from app.services.raw_config_io_service import (
+from app.exceptions import (
     ConfigDirError,
     ConfigFileExistsError,
     ConfigFileNameError,

backend/tests/test_services/test_file_config_service.py

@@ -8,12 +8,14 @@ import pytest
 
 from app.models.config import ActionConfigUpdate, FilterConfigUpdate, JailFileConfigUpdate
 from app.models.file_config import ConfFileCreateRequest, ConfFileUpdateRequest
-from app.services.raw_config_io_service import (
+from app.exceptions import (
     ConfigDirError,
     ConfigFileExistsError,
     ConfigFileNameError,
     ConfigFileNotFoundError,
     ConfigFileWriteError,
+)
+from app.services.raw_config_io_service import (
     _parse_enabled,
     _set_enabled_in_content,
     _validate_new_name,