✨ Add spaces concept (#1776)

packages/database/prisma/migrations/20250614110551_create_spaces/migration.sql

@@ -0,0 +1,17 @@
+INSERT INTO spaces (id, name, owner_id, created_at, updated_at)
+SELECT gen_random_uuid(), 'Personal', id, NOW(), NOW()
+FROM users
+WHERE NOT EXISTS (
+  SELECT 1 FROM spaces WHERE spaces.owner_id = users.id
+) ON CONFLICT DO NOTHING;
+
+-- Set space_id for polls
+UPDATE polls
+SET space_id = spaces.id
+FROM spaces
+WHERE polls.user_id = spaces.owner_id AND polls.space_id IS NULL;
+
+UPDATE subscriptions
+SET space_id = spaces.id
+FROM spaces
+WHERE subscriptions.user_id = spaces.owner_id AND subscriptions.space_id IS NULL;