test: add import mapping fixtures

[Sj14122004]

Summary

Adds sample CSV fixtures and expected column mappings for the import/export app.

Fixes #161

Acceptance criteria covered

• Added a sample product CSV with intentionally varied column names
• Added a sample customer CSV with intentionally varied column names
• Added expected source-to-application column mappings
• Added an invalid customer CSV with a clear expected error
• Documented how the fixtures support the local Community Edition import/export app
• No database import behavior was changed

How was it tested?

• node --test tests/import-mapping-fixtures.test.js
• All 4 focused tests pass
• git diff --check passes

The full npm test suite was also attempted, but it has unrelated existing environment/build failures, including missing jsdom/dotenv dependencies and missing frontend/public build output.

Checklist

• One focused change per PR
• No real customer, merchant, credential, payment, or production data included
• No database import behavior changed
• Fixtures are synthetic and intended for local testing/documentation

[sridharkalaibala]

Thanks for the focused contribution. This meets #161's data-only scope: the fixtures are synthetic, include products, customers, and an invalid customer case, and document the expected mappings without changing import behavior. I also verified the documented aliases against the current importer, git diff --check, and node --test tests/import-mapping-fixtures.test.js (4 passing tests).

GitHub has not published repository checks yet, so I’m leaving this pending rather than approving before CI runs. Please request review again once those checks are green.

[sridharkalaibala]

Approved. The current head preserves the reviewed synthetic, data-only import fixtures and mapping documentation. git diff --check and node --test tests/import-mapping-fixtures.test.js passed in focused validation, and all repository checks are now green, including Desktop and Packaging.

[github-actions]

Merged to develop. Anyone can test this - you do not need write access.

Try it at https://develop.posnic.io, or run it yourself:

git fetch origin develop && git checkout develop
npm install && npm --prefix api install
npm run dev   # then http://localhost:3000

When you have tested it, say what you did and what happened, and set
QA passed or QA failed. If you cannot set labels, just comment -
a maintainer will.

Reporting that something is broken is as useful as fixing it. It is
better found here than by a shopkeeper.