Feature/ai pr analyser

[aravindraju007]

This PR introduces a fully automated, "zero-click" AI Pull Request Analyzer. It evaluates PR size, calculates C++ Cyclomatic Complexity, and utilizes an LLM to generate a comprehensive PDF summary dashboard attached directly to the PR.

To respect the existing CMake build system and repository structure, all Python code is isolated within the tools/ai_pr_analyzer/ directory.

##Architectural Highlights

• Zero-Click CI/CD: Triggered via .github/workflows/pr_analyzer.yml on pull_request events.
• Optimized Execution: The GitHub Action runner isolates the Python execution so it does not interfere with the primary C++ CMake builds.
• Static Analysis: Integrates Python's lizard library for real-time C++ complexity grading.
• Artifact Delivery: Generates a PDF dashboard using weasyprint and automatically attaches it to the GitHub Actions run as a downloadable artifact.

##Configuration Required for Testing
To allow the GitHub Action to run successfully on this repository, a repository secret must be configured by an administrator:

1. Navigate to Settings > Secrets and variables > Actions
2. Add a new repository secret named GEMINI_API_KEY containing the valid API token.

Looking forward to your review and feedback on the implementation!