[AST-146793] Add standardized CLAUDE.md documentation

Add comprehensive CLAUDE.md file following the Cloud MD standardization template (epic AST-146793).

Includes:
- Project Overview (purpose, status, key features)
- Architecture (layered design, components, data flow)
- Repository Structure (complete folder mapping)
- Technology Stack (languages, frameworks, dependencies)
- Development Setup (prerequisites, build, debug)
- Coding Standards (naming, style, async/threading)
- Project Rules (constraints, branch naming, commit format)
- Testing Strategy (unit tests, integration tests, manual checklist)
- Known Issues (compilation error, limitations, workarounds)
- Database Schema (none - stateless)
- External Integrations (Checkmarx API, CLI, GitHub)
- Deployment Info (release process, VSIX artifacts)
- Performance Considerations (scan timing, memory, optimization)
- API/Endpoints/Interfaces (DTE automation, VS APIs)
- Security & Access (credential storage, code signing, audit)
- Logging (framework, levels, destinations, troubleshooting)
- Debugging Steps (common issues, solutions, debug mode)

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: cx-rahul-pidde