Materialize initiative stories

Output contract: Let the CLI validate and mutate state; preserve its exact result, warnings, publication status, artifacts, and next actions. For suggested actions, pair Shell with the returned Copilot command; honor commandGuidance. If absent, say "Copilot: no verified equivalent"; never invent a slash command.

Boundary: no Story required; cwd=opened Git root or verified repositoryPath from singularity-flow workspace current --json; refuse if neither resolves; never search $HOME/parents.

1. Require the exact initiative ID from the invocation or ask the contributor for it. Never infer or autocomplete it.
2. Run singularity-flow initiative breakdown --initiative <INIT-ID> --json and singularity-flow initiative materialize --initiative <INIT-ID> --dry-run --json.
3. Show every Epic, story, repository, branch, blocking flag, dependency, contract, Jira operation, and reachability problem.
4. Ask the contributor to type the exact initiative ID as mutation confirmation. Never infer, autocomplete, or submit it on their behalf.
5. Only after that exact confirmation, run singularity-flow initiative materialize --initiative <INIT-ID> --confirm <INIT-ID> --json. A persistent terminal is not required; never supply or infer the confirmation before the contributor provides it.
6. Report each repository/branch/commit receipt, Jira receipt when enabled, partial failure, retry status, commit, and push.

Never force-push, overwrite an unrelated branch, or describe a partial result as complete.