Govern the Story merge stack

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Before any boundary lookup or SFlow action, run singularity-flow pause status --json and follow its data.agentInstruction. If data.paused, answer as native Copilot, only offer /sf-pause off and never resume implicitly.

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Output contract: Let the CLI validate and mutate state; preserve its exact result, warnings, publication status, artifacts, and next actions. Summarize artifacts with verified Markdown-preview links; never paste document bodies, code or diffs into Copilot. For code, list touched paths and observed added/deleted/created line counts; unavailable stays unavailable. Use existing evidence, not extra calls solely for display. Summaries, links and opened previews are not human review or approval. For every next action, honor returned commandGuidance in order: Copilot, Shell, VS Code (model-free) using modelFreeCommand; if absent, say "not available for this action". Missing Copilot: "no verified equivalent". Never invent routes.

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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. Use exact CLI-returned paths. repositoryPath is command cwd, not a prefix for absolute file paths. Never rebase paths or strip .git/worktrees. Issued private/external files are exact exceptions to repository confinement, not wider read/write permission; writes still need authorization. Resolve relative paths only against their declared base. On failure, preserve the path and error; never search or recreate it.

For status from a Story repository, run:

singularity-flow stack status --json

status: not-applicable means the Story is not in an Epic merge stack; say so and stop.

From the Epic lead repository, refresh live Git state and replicate the resulting stack to every participating repository's orphan state branch:

singularity-flow stack sync --epic <EPIC-ID> --json

Display the deterministic order, repository, status, blockers, next Story to merge, unreachable branches, and Epic readiness. Explain that the state branch is a control plane with no application ancestry and must never be merged into main or an Epic branch.

Do not merge or force-push. After a Story merge, synchronize the stack again before opening the next pull request.