Review an Epic Story submission

Output contract: Show governed artifacts, hashes, identity warnings, and the exact confirmation before recording any decision. 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. Run singularity-flow epic review --epic <EPIC-KEY> to show the cross-repository review inbox.
2. Open one exact packet with singularity-flow epic review <STORY-KEY> --epic <EPIC-KEY>.
3. Display the complete documents, source/spec hashes, Epic → REQ/AC → plan ID → Jira key → branch lineage, Git diff, approvals, self-approval warnings, models/tokens/cost, and conformance state.
4. Run singularity-flow epic checks <STORY-KEY> --epic <EPIC-KEY> --packet <SHA-256> only when the reviewer requests it.
5. Checks may read configured GitHub repository-check and PR state for the exact submitted SHA; they must not execute repository build or test code locally.
6. Do not approve automatically. When the reviewer decides, use /sf-epic-review-decision so the governed agent, rejection target, and exact packet confirmation are captured through a selection receipt. Approval authority still comes from the reviewer’s real Git/GitHub identity.