Merge CLAUDE.md into AGENTS.md

[lennartkats-db]

Changes

This merges CLAUDE.md into AGENTS.md. The former will now be a symlink, just like .cursurrules.

Review

• This PR was AI-generated. As a human reviewer, I confirmed it just merges the files and then re-orders the sections in a sensible way. Only minimal phrasing rewrites were included.

[eng-dev-ecosystem-bot]

Run: 17693607991

	Env	✅​pass	🙈​skip
✅​	aws linux	312	526
✅​	aws windows	313	525
✅​	aws-ucws linux	424	424
✅​	aws-ucws windows	425	423
✅​	azure linux	312	525
✅​	azure windows	313	524
✅​	azure-ucws linux	424	423
✅​	azure-ucws windows	425	422
✅​	gcp linux	311	527
✅​	gcp windows	312	526

[github-actions]

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• PR number: 3506
• Commit SHA: d433ce0226d0674c9048d8699339e086a4276ccf

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