Add gitleaks secret scanning

[Adityav369]

Adds gitleaks GitHub Action for automated secret detection (SOC2/HIPAA compliance requirement).

[jazzberry-ai]

Bug Report

Name: Missing gitleaks configuration for SOC2/HIPAA compliance
Severity: Medium
Example test case: Add a custom API key or internal credential to the repository. The default gitleaks configuration will likely not detect it.
Description: The gitleaks workflow is missing custom configuration to detect secrets specific to the project and relevant to SOC2/HIPAA. This could lead to sensitive information being committed to the repository without detection. The gitleaks action should be configured with a .gitleaks.toml file in the repository defining custom rules for identifying project-specific secrets.

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