refactor: complete Task 2/3 geo decouple + exceptions centralization; mark as done

backend/app/exceptions.py

@@ -0,0 +1,23 @@
+"""Shared domain exception classes used across routers and services."""
+
+from __future__ import annotations
+
+
+class JailNotFoundError(Exception):
+    """Raised when a requested jail name does not exist."""
+
+
+class JailOperationError(Exception):
+    """Raised when a fail2ban jail operation fails."""
+
+
+class ConfigValidationError(Exception):
+    """Raised when config values fail validation before applying."""
+
+
+class ConfigOperationError(Exception):
+    """Raised when a config payload update or command fails."""
+
+
+class ServerOperationError(Exception):
+    """Raised when a server control command (e.g. refresh) fails."""