Refactor module schema handling and add sync mechanism

Redesigned entity and index management with methods to streamline schema updates and added a sync flag to signal required DB syncs post-build. Enhanced test coverage and functionality for schema modifications, including support for additional fields.

app/__test__/modules/AppMedia.spec.ts

@@ -1,7 +1,53 @@
-import { describe } from "bun:test";
+import { describe, expect, test } from "bun:test";
+import { createApp, registries } from "../../src";
+import { em, entity, text } from "../../src/data";
+import { StorageLocalAdapter } from "../../src/media/storage/adapters/StorageLocalAdapter";
 import { AppMedia } from "../../src/modules";
 import { moduleTestSuite } from "./module-test-suite";
 
 describe("AppMedia", () => {
    moduleTestSuite(AppMedia);
+
+   test("should allow additional fields", async () => {
+      registries.media.register("local", StorageLocalAdapter);
+
+      const app = createApp({
+         initialConfig: {
+            media: {
+               entity_name: "media",
+               enabled: true,
+               adapter: {
+                  type: "local",
+                  config: {
+                     path: "./"
+                  }
+               }
+            },
+            data: em({
+               media: entity("media", {
+                  additional: text()
+               })
+            }).toJSON()
+         }
+      });
+
+      await app.build();
+
+      const fields = app.modules.em.entity("media").fields.map((f) => f.name);
+      expect(fields).toContain("additional");
+      expect(fields).toEqual([
+         "id",
+         "additional",
+         "path",
+         "folder",
+         "mime_type",
+         "size",
+         "scope",
+         "etag",
+         "modified_at",
+         "reference",
+         "entity_id",
+         "metadata"
+      ]);
+   });
 });