Attach the Copilot session to durable Git state

<!-- sflow-copilot-pause -->

Start with singularity-flow session open --for-agent --json once; for explicit takeover with an exact ID use singularity-flow session takeover <WORK-ID> --for-agent --json instead. Carry exact workspace/repository selectors and requested --refresh; with an ID refresh synchronizes, not local-open. Both entries check pause before Git. If paused, only offer /sf-pause off. Reuse the matching result. No separate pause/workspace/session lookups. Without an ID show candidates and ask for an exact choice; never infer selection.

<!-- sflow-output-contract: explicit-selection -->

Output contract: Collect every required choice explicitly; never infer or preselect; preserve errors, 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; an exact selected workspace/repository is also valid before checkout exists; 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.

Already loaded: never call the skill tool for it ("Skill not found" is expected). Wait for each command to exit. Session setup only: no raw Git, source reads, edits, or lifecycle work. A deferred path is not cwd. Story discovery comes from the configured state ledger, not an application-branch scan. Attachment fetches only the selected Story branch. Missing or unrefreshable state is a diagnostic, not an empty roster. Preserve that refusal; never enumerate branches or search the filesystem as a fallback. Existing verified managed checkouts may still use the local open route.

Listings reuse advisory snapshots (default 30 minutes). source: local/remoteCheckedAt: null is not remote freshness; report it accurately. Forward /sf-session --refresh with the same selectors. Failed refresh invalidates old success: preserve the real error/deadline; relay remediationPlan steps in order (its condition first, then its refresh/open); never retry automatically. Help is not a transport repair. Listings never authorize attachment or approval.

1. Preserve explicit --workspace <WORKSPACE> --repository <REPOSITORY-ID>. Resolve partial selectors within that workspace or ask; never fill from active workspace/cwd. Otherwise reuse open's explicit active scope; host cwd must not override it. Never guess URLs.
2. Without a Work ID, reuse the matching entry; relay table verbatim and ask for an exact ID via ask_user or chat. Binding/first row is not selection. Stop if no choice. Rerun only after explicit scope change or refresh. Gaps: singularity-flow session candidates --json --diagnostics with returned selectors.
3. Run singularity-flow session open <WORK-ID> --for-agent --json with returned selectors, or reuse the matching entry. Managed local open fast-forwards (remoteSync; unavailable = opened as-is, maybe behind); only a missing Story/repository permits remote fallback. Require ready, exact workId and open/attach agent matching activeAgent (null for completed Stories) before using context/nextsteps. Relay refusals and stop; never merge, rebase, reset, force-checkout, stash or discard work.
4. Report work, commit, agent and phase from open; tell shell users to cd to repositoryPath. For each action preserve order, timing, reason, Copilot: <copilotCommand>, and Shell: <command> from that same object in nextsteps. Do not merge distinct actions or invent missing routes. /sf-agent requires an explicit override request.
5. For hook refusals, read singularity-flow logs --event hook --level warn; hook.session.initiative means no Story selection.
6. End the turn; do not continue into Story work.