Add a per-user invoice_starting_number setting (default 1) instead of
always starting invoice numbering at 001. Adds /api/settings endpoints,
a user_settings table, and a Číslování faktur panel in the account menu
where the user can pick the starting number for a year with no
invoices yet.
Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>
