Add referee assignment/eligibility system, team bulk-add, member Groups, and referee management dashboard with PDF export

Builds the referee workflow end to end: club-defined RefereeLevel/RefereeProfile
eligibility tied to teams, EventReferee assignment (member or external, with
fee/km payment tracking), an admin dashboard with KPI tiles, date-grouped game
tiles and range filters, and a downloadable payment form PDF modeled on the
club's existing paper document (using Club.legal_name when set). Also lands
team roster bulk-add, member mass-upload with family linking, and the
members.Group model, developed alongside this work.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

management/context_processors.py

@@ -29,6 +29,7 @@ _NAV_SECTIONS = {
     "member_delete": "member_list",
     "member_attach_family": "member_list",
     "member_grant_login": "member_list",
+    "member_referee_eligibility_update": "member_list",
     "member_detach_family": "member_list",
     "family_create": "member_list",
     "family_detail": "member_list",
@@ -46,12 +47,20 @@ _NAV_SECTIONS = {
     "role_list": "role_list",
     "role_create": "role_list",
     "role_revoke": "role_list",
+    "group_list": "group_list",
+    "group_create": "group_list",
+    "group_detail": "group_list",
+    "group_update": "group_list",
+    "group_delete": "group_list",
+    "group_bulk_add": "group_list",
+    "group_member_remove": "group_list",
     "team_list": "team_list",
     "team_create": "team_list",
     "team_update": "team_list",
     "team_delete": "team_list",
     "team_detail": "team_list",
     "team_roster_add": "team_list",
+    "team_bulk_add": "team_list",
     "team_roster_update": "team_list",
     "team_roster_remove": "team_list",
     "team_staff_add": "team_list",
@@ -59,6 +68,11 @@ _NAV_SECTIONS = {
     "team_staff_remove": "team_list",
     "team_photo_set": "team_list",
     "team_photo_delete": "team_list",
+    "referee_list": "referee_list",
+    "referee_management": "referee_management",
+    "referee_level_list": "referee_level_list",
+    "referee_level_create": "referee_level_list",
+    "referee_level_update": "referee_level_list",
     "news_list": "news_list",
     "news_create": "news_list",
     "news_detail": "news_list",
@@ -76,6 +90,11 @@ _NAV_SECTIONS = {
     "event_delete": "event_list",
     "event_detach": "event_list",
     "event_fetch_game_info": "event_list",
+    "event_referee_assign": "event_list",
+    "event_referee_add_external": "event_list",
+    "event_referee_remove": "event_list",
+    "event_referee_fee_update": "event_list",
+    "event_referee_form_pdf": "event_list",
     "rbihf_import": "event_list",
     "rbihf_import_confirm": "event_list",
     "event_series_create": "event_list",