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/db/users.sql.go

@@ -0,0 +1,50 @@
+// Code generated by sqlc. DO NOT EDIT.
+// versions:
+//   sqlc v1.31.1
+// source: users.sql
+
+package db
+
+import (
+	"context"
+
+	"github.com/google/uuid"
+)
+
+const createUser = `-- name: CreateUser :one
+INSERT INTO users (id, email, password_hash) VALUES ($1, $2, $3) RETURNING id, email, created_at, password_hash
+`
+
+type CreateUserParams struct {
+	ID           uuid.UUID `json:"id"`
+	Email        string    `json:"email"`
+	PasswordHash *string   `json:"password_hash"`
+}
+
+func (q *Queries) CreateUser(ctx context.Context, arg CreateUserParams) (User, error) {
+	row := q.db.QueryRow(ctx, createUser, arg.ID, arg.Email, arg.PasswordHash)
+	var i User
+	err := row.Scan(
+		&i.ID,
+		&i.Email,
+		&i.CreatedAt,
+		&i.PasswordHash,
+	)
+	return i, err
+}
+
+const getUserByEmail = `-- name: GetUserByEmail :one
+SELECT id, email, created_at, password_hash FROM users WHERE email = $1
+`
+
+func (q *Queries) GetUserByEmail(ctx context.Context, email string) (User, error) {
+	row := q.db.QueryRow(ctx, getUserByEmail, email)
+	var i User
+	err := row.Scan(
+		&i.ID,
+		&i.Email,
+		&i.CreatedAt,
+		&i.PasswordHash,
+	)
+	return i, err
+}