Wire provider streaming request lifecycle

AgentCompany-New/src/main/database/migrations/023-provider-request-runtime.ts

@@ -0,0 +1,12 @@
+export const providerRequestRuntimeSchema = `
+  alter table provider_requests add column external_response_id text;
+  alter table provider_requests add column stream_event_count integer not null default 0;
+  alter table provider_requests add column cancelled_at text;
+
+  create index if not exists idx_provider_requests_external_response
+    on provider_requests(provider_id, external_response_id)
+    where external_response_id is not null;
+
+  insert into schema_migrations(version, name, applied_at)
+  values (23, 'provider_request_runtime', datetime('now'));
+`;