CM-034 Integrate Symfony Lock Component

[ChernegaSergiy]

Implement Lock Mechanism for Critical Sections

User Story

As a developer, I want distributed locking for critical sections so concurrent operations are safe.

Acceptance Criteria

1. Add symfony/lock package to composer.json.
2. Implement locks for KPI calculations and inventory updates.
3. Add Redis/File-based lock stores.
4. Update calculate_kpis.php to use locks for data consistency.
5. Add lock timeout and retry logic.