Create users table

migrations/2026-06-25-233206-0000_create_users_table/up.sql

@@ -0,0 +1,8 @@
+CREATE TABLE users (
+    id INTEGER PRIMARY KEY UNIQUE NOT NULL GENERATED ALWAYS AS IDENTITY,
+    username VARCHAR UNIQUE NOT NULL,
+    hashed_password VARCHAR NOT NULL,
+    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
+);
+
+CREATE UNIQUE INDEX users_username_idx ON users(username);