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/20260830000010_workflow_revisions.js

@@ -0,0 +1,31 @@
+/**
+ * @param {import("knex").Knex} knex
+ */
+export async function up(knex) {
+  await knex.schema.createTable("workflow_revisions", (t) => {
+    t.text("id").primary();
+    t.text("workflow_id").notNullable();
+    t.text("owner").notNullable();
+    t.text("file").notNullable();
+    t.integer("revision").notNullable();
+    t.text("content_sha").notNullable();
+    t.text("content").notNullable();
+    t.text("reason");
+    t.text("meta");
+    t.text("created_at").notNullable();
+  });
+
+  await knex.schema.raw(
+    "CREATE UNIQUE INDEX workflow_revisions_workflow_id_revision_idx ON workflow_revisions (workflow_id, revision)",
+  );
+  await knex.schema.raw(
+    "CREATE INDEX workflow_revisions_workflow_id_created_at_idx ON workflow_revisions (workflow_id, created_at DESC)",
+  );
+}
+
+/**
+ * @param {import("knex").Knex} knex
+ */
+export async function down(knex) {
+  await knex.schema.dropTableIfExists("workflow_revisions");
+}