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/20260830000004_users.js

@@ -0,0 +1,20 @@
+/**
+ * @param {import("knex").Knex} knex
+ */
+export async function up(knex) {
+  await knex.schema.createTable("users", (t) => {
+    t.text("id").primary();
+    t.text("username").notNullable().unique();
+    t.text("password_hash").notNullable();
+    t.text("role").notNullable();
+    t.text("created_at").notNullable();
+    t.text("updated_at").notNullable();
+  });
+}
+
+/**
+ * @param {import("knex").Knex} knex
+ */
+export async function down(knex) {
+  await knex.schema.dropTableIfExists("users");
+}