Admin task: create and bootstrap sourceos-devtools repo

[mdheller]

Create SourceOS-Linux/sourceos-devtools as the SourceOS Developer Tools home.

Purpose:

• Linux-native developer tooling.
• Nix/devshell orchestration.
• NLBoot/operator tooling.
• Lab profile selection.
• Release tooling.
• Local AI governance utilities.
• SourceOS workstation bootstrap.

Suggested command:

gh repo create SourceOS-Linux/sourceos-devtools \
  --public \
  --add-readme \
  --description "SourceOS Developer Tools: Linux-native developer tooling, lab profile selection, Nix/devshell orchestration, release tooling, local AI governance utilities, and SourceOS workstation bootstrap." \
  --clone=false

After creation, add:

• README.md
• AGENTS.md
• .github/copilot-instructions.md
• docs/DEVTOOLS_SCOPE.md
• repo.maturity.yaml
• validation Makefile

Boundary:
This issue tracks a repo-creation/admin gap. Do not duplicate devtools implementation in sourceos-spec.

[mdheller]

Admin gap completed: SourceOS-Linux/sourceos-devtools now exists and has README scope, AGENTS.md, Copilot instructions, DEVTOOLS_SCOPE.md, repo.maturity.yaml, Makefile validation, validate workflow, and first scaffold issue SourceOS-Linux/sourceos-devtools#1 assigned to Copilot.