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-store-foundation/assets/split-frontend-agents-template.md

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+# AGENTS.md Template For Split Frontend Repo
+
+## Repo role
+- This repo owns the storefront and admin UI surface.
+- It consumes backend contracts from the paired backend repo.
+
+## Frontend scope
+- Storefront routes, account routes when needed, and admin routes or admin app.
+- Design system, responsive rules, motion rules, and accessibility baseline.
+
+## Data contract rules
+- Do not invent backend fields without documenting the contract.
+- Keep request and response assumptions aligned with the backend repo.
+
+## Asset workflow
+- Define source imagery, placeholder policy, and external generation prompt policy.
+
+## Delivery rules
+- Keep mobile storefront quality high.
+- Keep admin workflows efficient and reliable.