fix(security): resolve dependency vulnerabilities

[albonidrizi]

Summary

• upgrade Spring Boot and vulnerable transitive dependencies
• prepare Maven dependencies before Trivy filesystem scans
• keep Gitleaks running even when Trivy reports findings

Verification

• mvn clean verify (18 tests, coverage gates passed)
• Trivy HIGH/CRITICAL scan: 0 findings
• Gitleaks current tree scan: no leaks found

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud