[Epic 5] Templates contract + stub catalog (future cpa-templates)

[ulises-jeremias]

Summary

Define templates.json / cpa.config.json contracts and a local stub catalog for CI. Track future Create-Python-App/cpa-templates + website.

CNA mapping

Separate repo Create-Node-App/cna-templates + CLI catalog fetch.

Why

CLI cannot be validated without a catalog contract; full bank is later.

Sub-issues

• Specify templates.json schema parity with cna-templates #41 Specify templates.json schema parity with cna-templates
• Document cpa.config.json vs cna.config.json for Python #42 Document cpa.config.json vs cna.config.json for Python
• Local stub catalog under fixtures/ or examples/ for CI #43 Local stub catalog under fixtures/ or examples/ for CI
• Tracking: create Create-Python-App/cpa-templates + website later #44 Tracking: create Create-Python-App/cpa-templates + website later

Blocks / dependencies

Unblocks realistic catalog listing in #5/#38.

Blocked by: none for schema; stub needed for CI

Reference

Parity matrix (workspace): knowledge/create-python-app-parity-matrix.md
Reference repo: https://github.com/Create-Node-App/create-node-app

[ulises-jeremias]

Contract docs + stub fixtures landed; #44 remains open as tracker.