[Bug]: `/speckit.converge` can declare convergence without auditable acceptance-scenario coverage

[cadugevaerd]

Bug Description

/speckit.converge already requires one stable intent-inventory key per FR-###, buildable SC-###, and user-story acceptance scenario such as US1/AC2. However, its output contract exposes only a single undenominated line, Requirements / acceptance criteria checked.

An agent can therefore assess user stories in bulk, report a plausible aggregate (for example, 16 FR + 12 SC + 4 user stories), and still emit converged without exposing that only 4 user-story rows were checked instead of the 16 acceptance scenarios required by the inventory rule.

This is an observability/closure-contract defect rather than a missing inventory instruction: the prompt tells the agent what to assess, but the report cannot demonstrate whether it did so.

Steps to Reproduce

1. Run /speckit.converge after an implementation pass on a feature whose spec.md has multiple user-story acceptance scenarios.
2. Have the assessment aggregate user stories instead of evaluating each scenario key.
3. Observe that the report can satisfy the current summary-metrics text while omitting the number of scenarios assessed.
4. In the observed case, a second pass changed only the granularity from user stories to individual acceptance scenarios and surfaced a missing HIGH finding at US3/AC4; a third pass at the same granularity found no remaining gaps.

Expected Behavior

The convergence report should make completion independently auditable:

• report checked/total separately for buildable FRs, buildable SCs, user-story acceptance scenarios, plan decisions, and applicable Constitution MUST principles;
• derive each denominator from the artifacts loaded during the run, not from model memory;
• expose the stable inventory keys with a compact checked/gap/unassessed status;
• allow converged only when every applicable category is fully assessed and no findings remain;
• fail closed with a distinct incomplete_assessment result when any inventory key is unassessed, without appending a partial Convergence phase to tasks.md.

Actual Behavior

The current template requires the fine-grained inventory internally but only asks for aggregate summary labels. As a result, a report can look complete while concealing a mismatch such as 4 assessed user stories versus 16 required acceptance scenarios. A false converged would end the implementation/convergence loop with an unassessed HIGH requirement.

Specify CLI Version

0.14.3.dev0 (main at time of report)

AI Agent

Not applicable — this is a core command-template contract affecting all agent integrations.

Operating System

Linux 5.15.147-sun60iw2

Python Version

Python 3.13.5

Error Logs

No process error: the defect is a false-completeness reporting path.

Additional Context

Proposed focused change:

1. Update templates/commands/converge.md with denominated per-category coverage, an auditable key ledger, and the fail-closed outcome precedence incomplete_assessment → tasks_appended → converged.
2. Document the third outcome in the Agentic SDD reference.
3. Add a deterministic template-contract regression test plus manual command validation.

Searches of existing upstream Issues/PRs found no duplicate for converge coverage denominators or incomplete assessment.

AI disclosure: This report was prepared by Hermes Agent (OpenAI gpt-5.6-terra) on behalf of @cadugevaerd, using Carlos's observed three-pass evidence and current upstream source inspection.

[cadugevaerd]

Implementação proposta em #3754: adiciona métricas checked/total derivadas dos artefatos, ledger de chaves estáveis e o desfecho fail-closed incomplete_assessment antes de tasks_appended/converged.