feat: add crm dead-letter operations and benchmark summary

supabase/migrations/202606300018_crm_dead_letter_operations.sql

@@ -0,0 +1,42 @@
+alter table public.crm_webhook_queue
+  add column if not exists dead_lettered_at timestamptz,
+  add column if not exists ignored_at timestamptz,
+  add column if not exists ignored_by uuid references public.platform_users(id) on delete set null,
+  add column if not exists last_operator_user_id uuid references public.platform_users(id) on delete set null,
+  add column if not exists last_operator_action text,
+  add column if not exists last_operator_note text,
+  add column if not exists last_operator_at timestamptz,
+  add column if not exists operator_metadata jsonb not null default '{}'::jsonb;
+
+alter table public.crm_webhook_log
+  add column if not exists queue_id uuid references public.crm_webhook_queue(id) on delete set null,
+  add column if not exists operator_user_id uuid references public.platform_users(id) on delete set null,
+  add column if not exists operation text;
+
+update public.crm_webhook_queue
+set dead_lettered_at = coalesce(dead_lettered_at, updated_at, created_at)
+where status in ('failed', 'discarded') and dead_lettered_at is null;
+
+create index if not exists idx_crm_queue_dead_letters
+  on public.crm_webhook_queue(tenant_id, status, dead_lettered_at desc, updated_at desc)
+  where status in ('failed', 'discarded');
+
+create index if not exists idx_crm_queue_operator
+  on public.crm_webhook_queue(tenant_id, last_operator_at desc)
+  where last_operator_at is not null;
+
+create index if not exists idx_crm_webhook_log_queue
+  on public.crm_webhook_log(tenant_id, queue_id, created_at desc)
+  where queue_id is not null;
+
+comment on column public.crm_webhook_queue.dead_lettered_at is
+  'Set when a CRM webhook task reaches a terminal failed/discarded state and needs operator review.';
+
+comment on column public.crm_webhook_queue.ignored_at is
+  'Set when a tenant operator intentionally dismisses a CRM webhook dead-letter task.';
+
+comment on column public.crm_webhook_queue.last_operator_action is
+  'Last manual CRM queue operation, for example retry or ignore.';
+
+comment on column public.crm_webhook_log.queue_id is
+  'Direct reference to the CRM queue task. Older logs may only have record_id or lead_id.';