fix: unique user id in user session;

feat: login controller method;
fix: name validation hander

sqlc/schema.sql

@@ -41,7 +41,7 @@ CREATE TABLE IF NOT EXISTS "confirmation_codes" (
 
 CREATE TABLE IF NOT EXISTS "sessions" (
   id BIGSERIAL PRIMARY KEY,
-  user_id BIGINT UNIQUE NOT NULL REFERENCES users(id) ON DELETE CASCADE,
+  user_id BIGINT NOT NULL REFERENCES users(id) ON DELETE CASCADE,
   guid UUID NOT NULL DEFAULT gen_random_uuid(),
   name VARCHAR(100),
   platform VARCHAR(32),