feat: add Party management API with RESTful endpoints and comprehensive documentation

- Introduce Party model with lifecycle states (draft, published, canceled, sold_out)
- Add RESTful API endpoints under /api/v1/parties for CRUD operations
- Create ApiController base with API key authentication
- Implement comprehensive code comments across models and controllers
- Add database migration for parties table with proper indexes
- Configure API routes with namespaced versioning

db/migrate/20250823145902_create_parties.rb

@@ -0,0 +1,19 @@
+class CreateParties < ActiveRecord::Migration[8.0]
+  def change
+    create_table :parties do |t|
+      t.string :name, null: false
+      t.text :description, null: false
+      t.integer :state, default: 0, null: false
+      t.string :venue_name, null: false
+      t.string :venue_address, null: false
+      t.decimal :latitude, precision: 10, scale: 6, null: false
+      t.decimal :longitude, precision: 10, scale: 6, null: false
+      t.boolean :featured, default: false, null: false
+      t.timestamps
+    end
+
+    add_index :parties, :state
+    add_index :parties, :featured
+    add_index :parties, [:latitude, :longitude]
+  end
+end