Add Tiers and Game Prize

migrations/000050_create_tiers_table.up.sql

@@ -0,0 +1,14 @@
+CREATE TABLE tiers (
+    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
+    name VARCHAR(100) NOT NULL UNIQUE,
+    min_points BIGINT NOT NULL,
+    benefits JSONB DEFAULT '{}',
+    created_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    updated_at TIMESTAMP WITH TIME ZONE DEFAULT NOW(),
+    
+    CONSTRAINT chk_tiers_min_points_non_negative
+        CHECK (min_points >= 0)
+);
+
+CREATE INDEX idx_tiers_min_points ON tiers(min_points);
+CREATE INDEX idx_tiers_created_at ON tiers(created_at);