Turn my idea into a build-ready spec

I want to build [DESCRIBE YOUR IDEA IN A FEW SENTENCES]. Help me turn this into a clear product spec that an AI coding tool can build from.

First, ask me clarifying questions, in small batches, until you understand: who it is for, the single most important thing a user should be able to do, and what counts as done for a first version. Do not write the spec until you have enough to be specific.

Then write the spec with these sections:
1. One-paragraph summary of what the product is and who it serves.
2. The core user (who they are and what they want).
3. Version 1 features as a numbered list. Be ruthless. Anything not needed to prove the idea goes into a separate "Later" list.
4. User flows for the 2 or 3 main actions, written step by step.
5. The data the app needs to store (the main tables and their key fields).
6. The pages or screens needed, with what is on each.
7. Out of scope for v1, stated explicitly so nothing sneaks in.

Keep it plain and concrete. No jargon. The goal is something I can hand to Cursor, Lovable, or Claude Code and get a working first version.