fix: replace broad except Exception with specific exception types

- jail_service: catch ValueError (fail2ban protocol error) instead of Exception
- health.py: catch AttributeError (not OSError/TypeError) for defensive checks
- ban_service: re-raise programming errors in geo lookup handlers
- server_service: catch Fail2BanConnectionError, Fail2BanProtocolError, ValueError
- config_writer: catch OSError instead of Exception

Programming errors now bubble to global handler instead of being silently caught.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

backend/app/services/ban_service.py

@@ -481,6 +481,7 @@ async def list_bans(
                 log.warning("ban_service_geo_lookup_failed", ip=ip)
             except Exception as exc:
                 log.error("ban_service_geo_lookup_unexpected_error", ip=ip, error=type(exc).__name__)
+                raise  # Bubble programming errors to global handler
 
         items.append(
             DomainDashboardBanItem(
@@ -648,7 +649,7 @@ async def bans_by_country(
                 return ip, None
             except Exception as exc:
                 log.error("ban_service_geo_lookup_unexpected_error", ip=ip, error=type(exc).__name__)
-                return ip, None
+                raise  # Bubble programming errors to global handler
 
         results = await asyncio.gather(*(_safe_lookup(ip) for ip in unique_ips))
         geo_map = {ip: geo for ip, geo in results if geo is not None}