feat(api): add initial schema migration

backend/migrations/20260220000001_initial_schema.js

@@ -0,0 +1,11 @@
+export async function up(knex) {
+  await knex.schema.createTable('cv_data', (table) => {
+    table.integer('id').primary();
+    table.text('data').notNullable();
+    table.datetime('updated_at').defaultTo(knex.fn.now());
+  });
+}
+
+export async function down(knex) {
+  await knex.schema.dropTableIfExists('cv_data');
+}