feat(store): миграция sessions/password + методы users/sessions/projects

Фаза 2, Task 1: добавлена таблица sessions и nullable password_hash у
users, sqlc-запросы и *Store-обёртки (CreateUser, GetUserByEmail,
CreateProjectForUser, GetProjectOwned, GetUserProject, CreateSession,
GetSessionUser, DeleteSession, RegisterUser в транзакции), интеграционные
тесты на testcontainers.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01BwxdSt4reTm7Dj1oxRvpP3

internal/store/queries/projects.sql

@@ -0,0 +1,8 @@
+-- name: CreateProject :one
+INSERT INTO projects (id, user_id, name) VALUES ($1, $2, $3) RETURNING *;
+
+-- name: GetProjectOwned :one
+SELECT * FROM projects WHERE id = $1 AND user_id = $2;
+
+-- name: GetUserProject :one
+SELECT * FROM projects WHERE user_id = $1 ORDER BY created_at LIMIT 1;

internal/store/queries/sessions.sql

@@ -0,0 +1,8 @@
+-- name: CreateSession :exec
+INSERT INTO sessions (id, user_id, token_hash, expires_at) VALUES ($1, $2, $3, $4);
+
+-- name: GetSessionUser :one
+SELECT user_id FROM sessions WHERE token_hash = $1 AND expires_at > now();
+
+-- name: DeleteSession :exec
+DELETE FROM sessions WHERE token_hash = $1;

internal/store/queries/users.sql

@@ -0,0 +1,5 @@
+-- name: CreateUser :one
+INSERT INTO users (id, email, password_hash) VALUES ($1, $2, $3) RETURNING *;
+
+-- name: GetUserByEmail :one
+SELECT * FROM users WHERE email = $1;