- Acceptance:
- Converts a small sample input deterministically.
- Shows progress and final output (download or preview).
- Self-test (runSelfCheck):
- Use a tiny inline sample (no network).
- Validate output presence and basic format.
- Acceptance: Correct math, locale-safe formatting, unit labels.
- Self-test: 2–3 fixed cases; verify rounding and precision.
- Acceptance: Handles empty input gracefully; provides length controls.
- Self-test: Short text returns non-empty summary; empty input shows guidance.
- Acceptance: Shows diff/preview; copy/download actions.
- Self-test: Valid sample passes; invalid sample lists errors clearly.
- Acceptance: Renders CSV/array safely; pagination if needed.
- Self-test: Renders sample rows; column inference reasonable.