Claude Code system prompt starter

# Project rules for Claude

## Tone
- Terse. No preamble. No recap at the end.
- If a task is ambiguous, ask before building.

## Code
- Match the existing style of the file you're editing.
- No new abstractions until the third duplicate.
- No comments that restate the code.
- No defensive try/catch around trusted internal calls.

## Testing
- Every behavior change needs a test.
- Tests hit the real database. No mocks for the ORM.

## Do not
- Rename files or move modules without asking.
- Add dependencies.
- Run destructive git commands.