Help me define a bounded local data-specialist mission using only synthetic text, CSV, and JSON files. The application must run with Node.js and browser-native HTML, CSS, and JavaScript, use no external runtime dependencies or services, and keep all processing on my computer.

Restate the users, input contract, deterministic rules, evidence report, denied inputs, file and size limits, output boundary, security controls, tests, limitations, and definition of success. Separate behavior that requires reasoning during design from behavior that should remain deterministic at runtime.

Do not create code or a repository yet. Finish with a concise specification I can review, save as a project artifact, and copy into Codex.