[field 2026-10-13] existing-app-change: status stays at "Stage 1" through 4 delivered backlog rounds; no backlog-round track #301

Problem

In existing-app-change mode, delivery happened as a stream of small backlog stories in rounds (3–5 stories per round, tracked in a project-local stories.json). The toolkit's stage machine does not model that, so after 4 delivered rounds:

• status.sh --brief still reports "Stage 1 — Analysis, in progress — gates passed: P, 0"
• the WATCH line shows "agent slots unfilled: 35 in 6 file(s)" and "done- stalled" counts that say nothing about the delivered stories
• NEXT points at items unrelated to the round in flight

existing-app-change.md runs stages 1–4 per change (BRD per changed capability, build plan), which fits one larger change but not a backlog of 1–5 SP stories each needing scope → build → test → record.

Proposal

• A backlog-round track within existing-app-change: a standard per-story record (scope, touched units, decisions, gate rows, test verdict, manual steps), a round as the unit of status, and status.sh reading it ("Round 3: 3 stories, 2 verified, 1 in test").
• Suppress agent-slot / done- noise when the entry mode does not use them.
• Keep the map (Stage 0a) as the one-time prerequisite; stories link to it for blast radius.

Field context: a 127-module production Mendix 11.12 app (17,500 model units), 11 backlog features delivered in 4 rounds with Claude Code + mxcli v0.24 + this toolkit. Details anonymized.

🤖 Generated with Claude Code