refactor(config): remove legacy config reference handling and streamline YAML management

- Deleted legacy config reference handling functions and related migration scripts to simplify the codebase.
- Updated documentation to reflect the removal of legacy YAML paths and configurations.
- Adjusted existing YAML management processes to ensure compatibility with the new mustache-style syntax.
- Removed tests related to legacy config references, focusing on current functionality and ensuring clarity in the testing suite.

packages/server/migrations/20260830000002_step_runs.js

@@ -0,0 +1,33 @@
+/**
+ * @param {import("knex").Knex} knex
+ */
+export async function up(knex) {
+  await knex.schema.createTable("step_runs", (t) => {
+    t.text("id").primary();
+    t.text("run_id")
+      .notNullable()
+      .references("id")
+      .inTable("workflow_runs")
+      .onDelete("CASCADE");
+    t.integer("step_index").notNullable();
+    t.text("script").notNullable();
+    t.text("config");
+    t.text("status").notNullable();
+    t.text("started_at").notNullable();
+    t.text("finished_at");
+    t.integer("duration_ms");
+    t.text("output");
+    t.text("error");
+  });
+
+  await knex.schema.raw(
+    "CREATE INDEX step_runs_run_id_step_index_idx ON step_runs (run_id, step_index)",
+  );
+}
+
+/**
+ * @param {import("knex").Knex} knex
+ */
+export async function down(knex) {
+  await knex.schema.dropTableIfExists("step_runs");
+}