Replace WasItAIGenerated?

Build the closest honest consolation tool inspired by WasItAIGenerated. Do not claim it detects AI writing.
Use exactly this stack: Next.js 15 + TypeScript + SQLite.
Primary job: paste text, send it to one general language model, and record that model's opinion on how machine-like the writing reads, with its reasoning.
Start from an empty folder and create the complete working project.
Single-user and private by default; store everything locally.
Put every secret in .env and provide .env.example.
Show the result as an opinion with reasoning, never as a score, a percentage or a verdict - the whole point of this build is that it cannot measure what the paid product measures.
Put a permanent, non-dismissable notice in the UI and the README: this is one model's guess, it has no measured error rate, and it must never be used to accuse anyone of anything.
Include clear empty, loading, validation, success and failure states.
Add export so the user is not trapped in the app.
Accessible keyboard navigation, labels, focus states and sensible contrast.
Deliberately exclude these paid-product advantages: a trained classifier, a labelled corpus, a published false-positive rate, image/audio/video detection, per-sentence attribution.
Do not fake accuracy claims, benchmarks or compliance statements.
Write unit tests for the data model and one end-to-end smoke test of the core loop.
Create a README with setup, architecture, data location and an explicit limitations section.
Run the tests and build before finishing, then fix what fails.