[Omkar-git-hub]

Summary

Add Gitleaks secret detection to the Offlink GitHub Actions CI workflow.

What Changed

• Added Gitleaks secret detection to the existing CI workflow.
• Secret scanning runs after repository checkout.
• Existing Flutter CI checks remain unchanged:
  • Dart formatting
  • Flutter analyze
  • Flutter tests
  • Android debug build

Why

Introduce a lightweight AppSec security gate into the Offlink learning project.

The goal is to automatically detect accidentally committed secrets such as:

• API keys
• Tokens
• Passwords
• Private keys
• Other credential-like values

CI Flow

Checkout
→ Gitleaks Secret Detection
→ Flutter Setup
→ Dependencies
→ Format
→ Analyze
→ Tests
→ Android Build

Testing

• Verified existing Flutter CI configuration.
• Gitleaks configuration added to GitHub Actions.
• No application logic was changed.

Scope

This PR intentionally adds only secret detection.

Dependency vulnerability scanning, SAST, SBOM, DAST, and other advanced AppSec checks will be introduced separately as future learning steps.

Risk

No application runtime behavior is changed.
Only the CI pipeline is updated.