[EPIC] CI/CD pipeline (GitHub Actions)

[kirich1409]

Context

GitHub Actions workflow running build, tests, lint, and import-graph check on every PR and on push to main. Import-graph check enforces S8 (modules cannot import destructive APIs).

Goals

• Workflow runs on pull_request and push main.
• Swift build + test job on macos-latest.
• Lint job (swift-format or swiftlint, choice documented).
• Import-graph analysis job fails on unauthorised imports from DevsweepModules.

Child tasks

Will be added as sub-issues after task batch.

Exit criteria

• First green run on main.
• Status badge in README.

Related documents

• Research report §S8 Module-level isolation