Add prepared tenant export archives

backend/db/migrations/0054_tenant_export_jobs.sql

@@ -0,0 +1,19 @@
+CREATE TABLE IF NOT EXISTS "tenant_export_jobs" (
+    "id" uuid PRIMARY KEY DEFAULT gen_random_uuid() NOT NULL,
+    "created_at" timestamp with time zone DEFAULT now() NOT NULL,
+    "updated_at" timestamp with time zone,
+    "completed_at" timestamp with time zone,
+    "tenant_id" bigint NOT NULL REFERENCES "tenants"("id") ON DELETE cascade,
+    "created_by" uuid REFERENCES "auth_users"("id"),
+    "status" text DEFAULT 'queued' NOT NULL,
+    "filename" text NOT NULL,
+    "storage_path" text,
+    "content_type" text DEFAULT 'application/zip' NOT NULL,
+    "file_size" bigint,
+    "error" text,
+    "files_total" integer DEFAULT 0 NOT NULL,
+    "files_done" integer DEFAULT 0 NOT NULL
+);
+
+CREATE INDEX IF NOT EXISTS "tenant_export_jobs_tenant_status_idx"
+    ON "tenant_export_jobs" ("tenant_id", "status");