feat(tournaments): add partnership tracking and tournament management

Implement comprehensive partnership tracking system and tournament
management features including round-robin, single/double elimination,
and Swiss system pairings.

Changes:
- Add partnership_games and partnership_stats tables
- Implement PartnershipTracker service for recording partnership data
- Add tournament generator with multiple formats
- Create tournament management actions and views
- Add acceptance tests for partnership tracking
- Fix PartnershipTracker to use single snapshot per player per match
- Fix round-robin test to query by round_number instead of hardcoded ID

Note: All 8 acceptance tests now passing

app/actions/admin/tournaments/rounds/show.rb

@@ -0,0 +1,37 @@
+# frozen_string_literal: true
+
+module EuchreCamp
+  module Actions
+    module Admin
+      module Tournaments
+        module Rounds
+          class Show < EuchreCamp::Action
+            include Deps[
+              events_repo: 'repositories.events',
+              rounds_repo: 'repositories.tournament_rounds',
+              matchups_repo: 'repositories.bracket_matchups',
+              teams_repo: 'repositories.teams'
+            ]
+
+            def handle(request, response)
+              tournament_id = request.params[:id]
+              round_id = request.params[:round_id]
+
+              tournament = events_repo.by_id(tournament_id)
+              round = rounds_repo.by_event(tournament_id).find { |r| r[:id] == round_id.to_i }
+              matchups = matchups_repo.by_round(round_id)
+              teams = teams_repo.by_event(tournament_id)
+
+              response.render(view,
+                tournament: tournament,
+                round: round,
+                matchups: matchups,
+                teams: teams
+              )
+            end
+          end
+        end
+      end
+    end
+  end
+end