Yuka for halal and kosher

Build yuka for halal and kosher.

Context: Scan a barcode, get a plain answer: halal, kosher, neither, or unclear — and
which ingredient decided it.

Yuka works because it gives a verdict instead of a table of numbers. This needs
the same discipline: not a list of E-numbers for the shopper to interpret, but
one word and the reason behind it.

The hard part is not the app, it's the data. Certification bodies differ by
country and by school of thought, and an ingredient like gelatine or a mono- and
diglyceride can go either way depending on its source, which the label rarely
states. "Unclear" has to be a first-class answer or the whole thing loses trust
the first time it's wrong.

Probably starts in one country with one certification body and grows outward.

Requirements:
- Ship the smallest version that delivers the core value above, nothing more.
- Pick a stack you can deploy in a day, and state the choice before writing code.
- Handle the empty state, the error state and the offline case explicitly.
- Pricing to build toward: Free to scan — it stops being useful the moment it costs something in the aisle.
Money would come from brands paying to keep their certification data current,
which is a conflict that has to be handled openly.

Start by listing the screens, then build them one at a time.