Refactor ban management with domain models and mappers

- Add ban domain model for core business logic separation
- Implement mapper pattern for DTO/domain conversions
- Update ban service with new domain-driven approach
- Refactor router endpoints to use new architecture
- Add comprehensive mapper tests
- Update documentation with architecture changes

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

backend/app/routers/dashboard.py

@@ -34,6 +34,12 @@ from app.models.ban import (
     TimeRange,
 )
 from app.models.server import ServerStatus, ServerStatusResponse
+from app.mappers import (
+    map_domain_dashboard_ban_list_to_response,
+    map_domain_bans_by_country_to_response,
+    map_domain_ban_trend_to_response,
+    map_domain_bans_by_jail_to_response,
+)
 from app.services import ban_service
 from app.utils.constants import DEFAULT_PAGE_SIZE
 
@@ -121,7 +127,7 @@ async def get_dashboard_bans(
         :class:`~app.models.ban.DashboardBanListResponse` with paginated
         ban items and the total count for the selected window.
     """
-    return await ban_service.list_bans(
+    domain_result = await ban_service.list_bans(
         socket_path,
         range,
         source=source,
@@ -132,6 +138,7 @@ async def get_dashboard_bans(
         geo_cache=geo_cache,
         origin=origin,
     )
+    return map_domain_dashboard_ban_list_to_response(domain_result)
 
 
 @router.get(
@@ -180,7 +187,7 @@ async def get_bans_by_country(
         :class:`~app.models.ban.BansByCountryResponse` with per-country
         aggregation and the companion ban list.
     """
-    return await ban_service.bans_by_country(
+    domain_result = await ban_service.bans_by_country(
         socket_path,
         range,
         source=source,
@@ -191,6 +198,7 @@ async def get_bans_by_country(
         origin=origin,
         country_code=country_code,
     )
+    return map_domain_bans_by_country_to_response(domain_result)
 
 
 @router.get(
@@ -237,13 +245,14 @@ async def get_ban_trend(
         :class:`~app.models.ban.BanTrendResponse` with the ordered bucket
         list and the bucket-size label.
     """
-    return await ban_service.ban_trend(
+    domain_result = await ban_service.ban_trend(
         socket_path,
         range,
         source=source,
         app_db=ban_ctx.db,
         origin=origin,
     )
+    return map_domain_ban_trend_to_response(domain_result)
 
 
 @router.get(
@@ -283,10 +292,11 @@ async def get_bans_by_jail(
         :class:`~app.models.ban.BansByJailResponse` with per-jail counts
         sorted descending and the total for the selected window.
     """
-    return await ban_service.bans_by_jail(
+    domain_result = await ban_service.bans_by_jail(
         socket_path,
         range,
         source=source,
         app_db=ban_ctx.db,
         origin=origin,
     )
+    return map_domain_bans_by_jail_to_response(domain_result)