feat: build entire backend into single executable (including migrations etc)

scripts/migrate/008_data_exports.sql

@@ -0,0 +1,10 @@
+-- +migrate Up
+
+-- 2023-03-15: Add data export
+
+create table data_exports (
+    id         serial primary key,
+    user_id    text not null references users (id) on delete cascade,
+    hash       text not null,
+    created_at timestamptz not null default now()
+);