T-10: Fix get_geo_batch_lookup for proper injection with GeoCache instance

Instead of returning a bound method (geo_cache.lookup_batch), now inject
the GeoCache instance directly into routers and services. This provides
proper runtime isolation since T-04 made GeoCache a proper object.

Changes:
- Remove get_geo_batch_lookup() dependency provider
- Add GeoCacheDep type alias for injecting GeoCache instances
- Update all routers (bans, blocklist, dashboard, jails) to use GeoCacheDep
- Update ban_service, blocklist_service, jail_service to accept GeoCache
- Update service protocols to match new signatures
- Update docstrings to reference GeoCache methods instead of module functions

All callers now call geo_cache.lookup_batch(...) directly instead of
geo_batch_lookup(...), providing real dependency injection with proper
testing isolation.

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

backend/app/routers/dashboard.py

@@ -21,7 +21,7 @@ from app.dependencies import (
     AuthDep,
     DbDep,
     Fail2BanSocketDep,
-    GeoBatchLookupDep,
+    GeoCacheDep,
     HttpSessionDep,
     ServerStatusDep,
 )
@@ -84,7 +84,7 @@ async def get_dashboard_bans(
     db: DbDep,
     socket_path: Fail2BanSocketDep,
     http_session: HttpSessionDep,
-    geo_batch_lookup: GeoBatchLookupDep,
+    geo_cache: GeoCacheDep,
     range: TimeRange = Query(default=_DEFAULT_RANGE, description="Time-range preset."),
     source: Literal["fail2ban", "archive"] = Query(
         default="fail2ban",
@@ -125,7 +125,7 @@ async def get_dashboard_bans(
         page_size=page_size,
         http_session=http_session,
         app_db=db,
-        geo_batch_lookup=geo_batch_lookup,
+        geo_cache=geo_cache,
         origin=origin,
     )
 
@@ -140,7 +140,7 @@ async def get_bans_by_country(
     db: DbDep,
     socket_path: Fail2BanSocketDep,
     http_session: HttpSessionDep,
-    geo_batch_lookup: GeoBatchLookupDep,
+    geo_cache: GeoCacheDep,
     range: TimeRange = Query(default=_DEFAULT_RANGE, description="Time-range preset."),
     source: Literal["fail2ban", "archive"] = Query(
         default="fail2ban",
@@ -177,8 +177,8 @@ async def get_bans_by_country(
         range,
         source=source,
         http_session=http_session,
-        geo_cache_lookup=geo_service.lookup_cached_only,
-        geo_batch_lookup=geo_batch_lookup,
+        geo_cache_lookup=geo_cache.lookup_cached_only,
+        geo_cache=geo_cache,
         app_db=db,
         origin=origin,
         country_code=country_code,