v7.0.0

Removed — BREAKING

• The unity-build.yml family of reusable workflows (deprecated since
  6.23.0): unity-build.yml, unity-build-android.yml,
  unity-build-webgl.yml, unity-build-linux.yml, unity-build-ios.yml,
  unity-build-gameci.yml, unity-validate.yml, unity-test.yml,
  unity-test-ios.yml, unity-nightly.yml, unity-release.yml and
  unity-release-ios.yml. Nothing in the current flow or the numbered
  consumer templates called them.
• The templates project-workflow.yml and consumer-unity-build.yml, and
  examples/sample-unity-project-integration/.
• The ten composite actions that only those workflows used:
  activate-unity, build-ios, build-unity, collect-container-output,
  discord-notify, resolve-unity-image, restore-docker-cache,
  run-unity-container, upload-build-report and validate-unity-project.
• docs/ADD_NEW_PROJECT.md (onboarding for the removed flow), replaced by
  docs/CONSUMER_SETUP.md.

Migration: docs/MIGRATION_V7.md. A project that
calls only unity-pipeline.yml and pipeline-*-release.yml moves from @v6
to @v7 with no other change. @v6 stays at the last 6.x release for projects that have
not moved. The consumer templates now pin @v7.

Changed

• With the native iOS route gone, every lane's build entry point can be
  overridden by build-method / UNITY_BUILD_METHOD. The "two iOS routes,
  two entry points" inconsistency documented in docs/ARCHITECTURE.md and
  CLAUDE.md no longer exists.