Add initial devcontainer configuration

[1davidjacky-commits]

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Summary by cubic

Add an initial .devcontainer configuration to provide a consistent VS Code/Codespaces environment. Uses the universal image mcr.microsoft.com/devcontainers/universal:2 with no additional features yet.

^{Written for commit 86c322a. Summary will update automatically on new commits.}

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[cubic-dev-ai]

No issues found across 1 file

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I've created PR #9307 with documentation updates for the devcontainer configuration added in this PR.

The documentation adds information about using development containers (both VS Code Dev Containers and GitHub Codespaces) as an alternative environment setup method in CONTRIBUTING.md.