feat(rate-limiter): add RateLimiter service, unit tests, and GitHub Actions CI

[Akisolu]

Description

The Rate Limiting service powered by Redis is implemented to prevent abuse of anonymous feedback requests, along with the complete configuration of the unit test suite and CI pipeline in GitHub Actions.

Included Changes

• RateLimiter Service (src/Services/RateLimiter.php):
• Implementation of tooManyAttempts, hit, attempts, and resetAttempts on top of Predis.
• Atomic expiration control (600s TTL by default) on the first request.
• Unit Tests (tests/Unit/RateLimiterTest.php):
• Full TDD coverage for verifying requests below the limit, blocking when exceeding it, and resetting counters.
• Continuous Integration (.github/workflows/ci.yml):
• Automation of executions with PHP 8.2+.
• Orchestration of containerized services for PostgreSQL 15 and Redis 7.

Verification

• Unit and integration tests executed locally with vendor/bin/phpunit (3/3 tests passed).
• Autoloading validated according to the PSR-4 standard.
• GitHub Actions pipeline executed successfully.