Amended request creates new submission entry with 'Amended Request' label

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

supabase/schema.sql

@@ -55,7 +55,7 @@ create table public.submissions (
   id uuid default gen_random_uuid() primary key,
   task_id uuid references public.tasks(id) on delete cascade not null,
   version_number integer not null,
-  type text not null check (type in ('initial', 'revision')) default 'initial',
+  type text not null check (type in ('initial', 'revision', 'amendment')) default 'initial',
   service_type text default '',
   deadline date,
   description text default '',