Publish a composition-first greenfield app case study with effort evidence

[enricopiovesan]

Problem

There is no evidence for the library-density threshold at which composing governed capabilities becomes more efficient than rebuilding business logic.

Scope

Create a small but credible greenfield reference app primarily assembled from existing published capabilities and document the composition/effect evidence.

Definition of done

• The app has a documented user-facing goal and uses a declared majority of existing published capabilities for its business flow.
• The repository identifies every composed capability, its version, contract, and application-specific glue.
• Reproducible build, execution, and failure-path commands are provided with safe trace outputs.
• The case study reports bounded effort evidence: capability reuse count, custom-code surface, and a clearly labeled qualitative or measured token/authoring comparison.
• The comparison names its assumptions and does not claim universal productivity gains.
• CI verifies the example uses the published consumption path and preserves the declared workflow behavior.
• The resulting cross-cutting capability gaps are listed as follow-up issues rather than silently mocked.

Governance

Use existing workflow-composition and public-consumption contracts; no new runtime authority is required.

[enricopiovesan]

Governance audit

No new spec or ADR is required. This is a bounded reference-app case study under existing workflow-composition and public-consumption governance. It must not introduce automatic publication, a new runtime planner authority, or ungoverned telemetry.