Add test coverage checklist, report template, and stack matrix for ecommerce project

- Created a test coverage checklist to ensure comprehensive testing of backend and frontend components.
- Added a test report template to standardize reporting on test execution results and gaps.
- Introduced a test stack matrix to guide the selection of testing tools and frameworks for backend and frontend.
- Established a skill for repairing failing tests, including a failure triage checklist and a test repair template.
- Documented recommended MCP stack for ecommerce development with FastAPI and React/Next.js.
- Developed a detailed README outlining the project structure, agent capabilities, and recommended workflows.
- Compiled a comprehensive workflow guide detailing step-by-step commands for project setup, testing, and SEO implementation.

site-fullstack/.github/skills/ecommerce-brief-preparation/assets/store-brief-template.md

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+# STORE-BRIEF.md Template
+
+## 1. Project Summary
+- Store name or working title
+- Business model
+- Target audience
+- Market or geography
+
+## 2. Delivery Mode
+- Monorepo or split repos
+- Current repo scope
+- Assumptions about paired repo responsibilities when applicable
+
+## 3. Technical Stack
+- Backend stack
+- Frontend stack
+- Database
+- Hosting or infrastructure assumptions
+
+## 4. Storefront Scope
+- Required pages
+- Catalog behavior
+- Search, filters, sorting
+- Auth and account needs
+- Cart and checkout or lead flow
+
+## 5. Admin or Back Office Scope
+- Required modules
+- Roles and permissions
+- Operational workflows
+
+## 6. Data and Domain Model
+- Core entities
+- Relationships
+- Inventory, pricing, promotions, order states
+
+## 7. Integrations
+- Payments
+- Delivery
+- CRM or ERP
+- Analytics
+- Media or storage
+
+## 8. UX and Visual Direction
+- Brand tone
+- UI direction
+- Motion expectations
+- Mobile-first expectations
+
+## 9. Assets and Content
+- Existing assets
+- Missing assets
+- External image prompt needs
+
+## 10. Clarified Answers
+- List the questions asked and the confirmed decisions
+
+## 11. Assumptions and Risks
+- Assumptions used for implementation
+- Open issues that can affect scope or architecture
+
+## 12. AGENTS.md Plan
+- What AGENTS.md should include for this repo or monorepo
+
+## 13. Build Phases
+- Phase 1: contracts and schema
+- Phase 2: storefront
+- Phase 3: admin panel or back office
+- Phase 4: polish, assets, QA