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/repositories/events.rb

@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+
+require 'rom-repository'
+
+module EuchreCamp
+  module Repositories
+    class Events < ::EuchreCamp::Repository[:events]
+      commands :create, update: :by_pk, delete: :by_pk
+
+      def all
+        events.to_a
+      end
+
+      def by_id(id)
+        events.by_pk(id).one!
+      end
+
+      def upcoming
+        events.where(status: ['planned', 'active']).order(:event_date).to_a
+      end
+
+      def completed
+        events.where(status: 'completed').order(Sequel.desc(:event_date)).to_a
+      end
+    end
+  end
+end