Add CLAUDE.md for Claude Code onboarding (AST-146794)

[cx-anurag-dalke]

Summary

• Adds comprehensive CLAUDE.md file to guide Claude Code when working in this repository
• Covers project architecture (layered design, plugin ecosystem context), development setup (build, test, lint, coverage commands), testing strategy (unit/integration patterns, coverage thresholds, test file rules), deployment process, proxy configuration, debugging steps, and contributing guidelines
• References internal Confluence documentation (Architecture Plugins, CLI Handover pages)

Test plan

• Verify CLAUDE.md renders correctly on GitHub
• Confirm all referenced file paths and commands are accurate
• Validate Confluence links are accessible

Generated with Claude Code

[github-actions]

Checkmarx One – Scan Summary & Details – 250104a8-289c-4ad5-b9a8-f2267436f3b9

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New Issues (1)

Checkmarx found the following issues in this Pull Request

#	Severity	Issue	Source File / Package	Checkmarx Insight
1		CVE-2026-35172	Go-github.com/distribution/distribution/v3-v3.0.1-0.20250403190400-dbca4995c83c	details Description: Distribution is a toolkit to pack, ship, store, and deliver container content. Prior to 3.1.0, distribution can restore read access in repo a after... Attack Vector: NETWORK Attack Complexity: LOW Vulnerable Package