This commit integrates pip-audit to enforce vulnerability checks in CI. Dependencies with unresolved HIGH/CRITICAL vulnerabilities will block builds unless explicitly allowlisted. The process is documented, with a strict policy to ensure exceptions are trackable and time-limited.
Updated the README to include a centralized NexaPG logo and detailed UI previews of key application sections such as dashboard, targets management, query insights, and others. Added new screenshot assets to the `docs/screenshots` directory to support the visual updates.
