Add Elo rating system with match entry and CSV upload

- Implement EloCalculator service for 2v2 Euchre matches
- Create background job processing with GoodJob
- Add single match entry form
- Add CSV upload for batch match entry
- Create player rankings view
- Add database schema for matches and elo snapshots

db/migrate/20240915000001_create_matches_and_elo_snapshots.rb

@@ -0,0 +1,42 @@
+# frozen_string_literal: true
+
+ROM::SQL.migration do
+  change do
+    # Drop and recreate matches table with new structure
+    drop_table?(:matches)
+    
+    create_table :matches do
+      primary_key :id
+      foreign_key :event_id, :events
+      column :played_at, DateTime
+      column :team_1_p1_id, Integer
+      column :team_1_p2_id, Integer
+      column :team_2_p1_id, Integer
+      column :team_2_p2_id, Integer
+      column :team_1_score, Integer
+      column :team_2_score, Integer
+      column :status, String, default: 'completed'
+    end
+
+    # Add current_elo to players table
+    alter_table :players do
+      add_column :current_elo, Integer, default: 1000
+    end
+
+    # Create elo_snapshots table
+    create_table :elo_snapshots do
+      primary_key :id
+      foreign_key :player_id, :players, null: false
+      foreign_key :match_id, :matches, null: false
+      column :rating_before, Integer, null: false
+      column :rating_after, Integer, null: false
+      column :rating_change, Integer, null: false
+      column :created_at, DateTime, null: false, default: Sequel::CURRENT_TIMESTAMP
+    end
+
+    # Add indexes for performance
+    add_index :elo_snapshots, [:player_id, :match_id], unique: true
+    add_index :matches, :played_at
+    add_index :matches, :status
+  end
+end