FEATURE REQUEST:CI/CD infrastructure for Ell-ena to automate testing,

### Is your feature request related to a problem?

- [x] Yes, it is related to a problem

### Describe the feature you'd like

## 🌟 Feature Description
Introduce a comprehensive CI/CD infrastructure for Ell-ena to automate testing, enforce linting standards, improve security scanning, and strengthen overall code quality.

This includes:
- Continuous Integration workflow
- Security analysis (CodeQL + dependency scanning)
- Automated dependency updates (Dependabot)
- Code ownership enforcement
- Strict linting configuration

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## 🔍 Problem Statement

Currently, the repository lacks automated validation mechanisms for:

- Static code analysis
- Unit testing
- Build validation
- Dependency vulnerability detection
- Code quality enforcement
- Automated reviewer assignment

Without CI/CD:

- Breaking changes can be merged unnoticed
- Performance regressions may go undetected
- Security vulnerabilities may remain hidden
- Code style inconsistencies accumulate over time
- Dependency updates are manual and error-prone

This increases long-term maintenance risk and slows scalable development.

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## 🎯 Expected Outcome

After implementation:

- Every Pull Request is automatically validated.
- Static analysis (`flutter analyze`) runs automatically.
- Unit tests execute with coverage reporting.
- Android & iOS builds are validated in CI.
- Code formatting and lint rules are enforced.
- Vulnerability scanning runs via CodeQL.
- Outdated dependencies are auto-detected and raised as PRs.
- Code owners are automatically assigned for review.

This establishes a production-grade development workflow and reduces regression risks significantly.

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## 📷 Screenshots and Design Ideas

Not UI-related.

Infrastructure design includes:

- `.github/workflows/ci.yml` for main validation pipeline
- `.github/workflows/security.yml` for vulnerability scanning
- `.github/dependabot.yml` for automated dependency updates
- `.github/CODEOWNERS` for structured reviews
- Enhanced `analysis_options.yaml` for stricter lint enforcement

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## 📋 Additional Context

This feature serves as foundational infrastructure for the project and aligns with best practices for modern Flutter-based production systems.

It also prepares the repository for:
- Future scaling
- Contributor growth
- Automated release workflows
- Stronger DevSecOps practices

I would like to work on implementing this CI/CD enhancement.

### Record

- [x] I agree to follow this project's Code of Conduct
- [x] I want to work on implementing this feature