feat(user): sqlc queries for users and sessions

internal/user/queries/users.sql

@@ -1,2 +1,38 @@
--- name: Ping :one
-SELECT 1::int AS ok;
+-- name: CreateUser :one
+INSERT INTO users (id, email, password_hash, display_name, is_admin)
+VALUES ($1, $2, $3, $4, $5)
+RETURNING id, email, password_hash, display_name, is_admin, created_at, updated_at;
+
+-- name: GetUserByEmail :one
+SELECT id, email, password_hash, display_name, is_admin, created_at, updated_at
+FROM users
+WHERE email = $1;
+
+-- name: GetUserByID :one
+SELECT id, email, password_hash, display_name, is_admin, created_at, updated_at
+FROM users
+WHERE id = $1;
+
+-- name: CountUsers :one
+SELECT COUNT(*)::int FROM users;
+
+-- name: CreateSession :exec
+INSERT INTO user_sessions (id, user_id, token_hash, expires_at)
+VALUES ($1, $2, $3, $4);
+
+-- name: GetSessionByTokenHash :one
+SELECT id, user_id, token_hash, expires_at, last_seen_at, created_at
+FROM user_sessions
+WHERE token_hash = $1
+  AND expires_at > now();
+
+-- name: TouchSession :exec
+UPDATE user_sessions
+SET last_seen_at = now()
+WHERE token_hash = $1;
+
+-- name: DeleteSessionByTokenHash :exec
+DELETE FROM user_sessions WHERE token_hash = $1;
+
+-- name: DeleteExpiredSessions :exec
+DELETE FROM user_sessions WHERE expires_at <= now();