diff --git a/web/app/index.html b/web/app/index.html
index fea40c68f..107950131 100644
--- a/web/app/index.html
+++ b/web/app/index.html
@@ -5,6 +5,8 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <meta name="theme-color" content="#202124" />
     <title>Web Blender Modeler V1</title>
+    <link rel="preload" as="fetch" type="application/wasm" crossorigin href="/vendor/blender/single/web_engine.wasm" />
+    <link rel="stylesheet" href="/src/app/app-shell.css" />
   </head>
   <body>
     <div id="root"></div>
diff --git a/web/app/public/wasm-module-manifest.json b/web/app/public/wasm-module-manifest.json
index fe6c8344c..5c6a81bb6 100644
--- a/web/app/public/wasm-module-manifest.json
+++ b/web/app/public/wasm-module-manifest.json
@@ -3,26 +3,9 @@
   "releaseId": "blender-wasm-0.1.0-rc.1",
   "modules": [
     {
-      "id": "core-completed",
+      "id": "core-runtime-completed",
       "lifecycle": "complete",
       "preload": true,
-      "resources": {
-        "single": {
-          "fileName": "web_engine.wasm",
-          "url": "/vendor/blender/web_engine.wasm",
-          "sha256": "66fc59cba55a8c17d398b74d12ea4a9f09746c0f30c40f579c44aa34956e3072"
-        },
-        "pthread": {
-          "fileName": "web_engine.wasm",
-          "url": "/vendor/blender/pthread/web_engine.wasm",
-          "sha256": "f2a26a9221b5d4d5e710463a89e2d93faf9b2d8a9076a455c5ce1a0e52d88b5f"
-        }
-      }
-    },
-    {
-      "id": "debug-incremental",
-      "lifecycle": "debug",
-      "preload": false,
       "resources": {
         "single": {
           "fileName": "web_engine.wasm",
@@ -35,6 +18,41 @@
           "sha256": "f2a26a9221b5d4d5e710463a89e2d93faf9b2d8a9076a455c5ce1a0e52d88b5f"
         }
       }
+    },
+    {
+      "id": "mesh-editing-completed",
+      "lifecycle": "complete",
+      "preload": true,
+      "resources": {
+        "single": { "fileName": "web_engine.wasm", "url": "/vendor/blender/single/web_engine.wasm", "sha256": "7f3a50f1d41b2ac0e6366e84caaabefc3cdfc47c055d5ea459abec654da6fcc0" },
+        "pthread": { "fileName": "web_engine.wasm", "url": "/vendor/blender/pthread/web_engine.wasm", "sha256": "f2a26a9221b5d4d5e710463a89e2d93faf9b2d8a9076a455c5ce1a0e52d88b5f" }
+      }
+    },
+    {
+      "id": "reader-capabilities-completed",
+      "lifecycle": "complete",
+      "preload": true,
+      "resources": {
+        "single": { "fileName": "web_engine.wasm", "url": "/vendor/blender/single/web_engine.wasm", "sha256": "7f3a50f1d41b2ac0e6366e84caaabefc3cdfc47c055d5ea459abec654da6fcc0" },
+        "pthread": { "fileName": "web_engine.wasm", "url": "/vendor/blender/pthread/web_engine.wasm", "sha256": "f2a26a9221b5d4d5e710463a89e2d93faf9b2d8a9076a455c5ce1a0e52d88b5f" }
+      }
+    },
+    {
+      "id": "debug-incremental",
+      "lifecycle": "debug",
+      "preload": false,
+      "resources": {
+        "single": {
+          "fileName": "web_engine.wasm",
+          "url": "/vendor/blender/web_engine.wasm",
+          "sha256": "66fc59cba55a8c17d398b74d12ea4a9f09746c0f30c40f579c44aa34956e3072"
+        },
+        "pthread": {
+          "fileName": "web_engine.wasm",
+          "url": "/vendor/blender/pthread/web_engine.wasm",
+          "sha256": "f2a26a9221b5d4d5e710463a89e2d93faf9b2d8a9076a455c5ce1a0e52d88b5f"
+        }
+      }
     }
   ]
 }
diff --git a/web/app/src/engine-client/WebEngineClient.ts b/web/app/src/engine-client/WebEngineClient.ts
index a34edc4a4..f05dcfb18 100644
--- a/web/app/src/engine-client/WebEngineClient.ts
+++ b/web/app/src/engine-client/WebEngineClient.ts
@@ -83,6 +83,17 @@ export class WebEngineClient {
     return (await this.request({ type: "init" })).status;
   }
 
+  async shutdown(): Promise<void> {
+    if (!this.worker) return;
+    try {
+      await this.request({ type: "shutdown" });
+    }
+    finally {
+      this.worker?.terminate();
+      this.worker = null;
+    }
+  }
+
   /** Load one debug WASM module without replacing the completed engine module. */
   async loadDebugWasmModule(id: string): Promise<NonNullable<WebEngineResult["wasmModules"]>> {
     const result = await this.request({ type: "loadWasmModule", id });
diff --git a/web/app/src/engine-client/wasm-module-loader.ts b/web/app/src/engine-client/wasm-module-loader.ts
index 0719c0f6b..e908835cd 100644
--- a/web/app/src/engine-client/wasm-module-loader.ts
+++ b/web/app/src/engine-client/wasm-module-loader.ts
@@ -37,20 +37,27 @@ export function createWasmModuleLoader(
   const bytes = new Map<string, ArrayBuffer>();
   const statuses = new Map<string, WasmModuleState>(manifest.modules.map((entry) => [entry.id, { id: entry.id, lifecycle: entry.lifecycle, status: "pending", byteLength: 0 }]));
   const loading = new Map<string, Promise<ArrayBuffer>>();
+  const markLoaded = (entry: WasmModuleEntry, value: ArrayBuffer): ArrayBuffer => {
+    statuses.set(entry.id, { id: entry.id, lifecycle: entry.lifecycle, status: "loaded", byteLength: value.byteLength });
+    return value;
+  };
   const load = (entry: WasmModuleEntry): Promise<ArrayBuffer> => {
-    const existing = bytes.get(entry.id);
-    if (existing) return Promise.resolve(existing);
-    const active = loading.get(entry.id);
-    if (active) return active;
-    const promise = fetchVerified(entry.resources[variant], fetcher).then((value) => {
-      bytes.set(entry.id, value);
-      statuses.set(entry.id, { id: entry.id, lifecycle: entry.lifecycle, status: "loaded", byteLength: value.byteLength });
-      return value;
+    const resource = entry.resources[variant];
+    const existing = bytes.get(resource.url);
+    if (existing) return Promise.resolve(markLoaded(entry, existing));
+    const active = loading.get(resource.url);
+    if (active) return active.then((value) => markLoaded(entry, value), (error: unknown) => {
+      statuses.set(entry.id, { id: entry.id, lifecycle: entry.lifecycle, status: "failed", byteLength: 0, error: error instanceof Error ? error.message : String(error) });
+      throw error;
+    });
+    const promise = fetchVerified(resource, fetcher).then((value) => {
+      bytes.set(resource.url, value);
+      return markLoaded(entry, value);
     }).catch((error: unknown) => {
       statuses.set(entry.id, { id: entry.id, lifecycle: entry.lifecycle, status: "failed", byteLength: 0, error: error instanceof Error ? error.message : String(error) });
       throw error;
-    }).finally(() => loading.delete(entry.id));
-    loading.set(entry.id, promise);
+    }).finally(() => loading.delete(resource.url));
+    loading.set(resource.url, promise);
     return promise;
   };
   return {
diff --git a/web/app/src/workers/web-engine.worker.ts b/web/app/src/workers/web-engine.worker.ts
index c3dba4071..3de260925 100644
--- a/web/app/src/workers/web-engine.worker.ts
+++ b/web/app/src/workers/web-engine.worker.ts
@@ -961,7 +961,7 @@ async function initialize(): Promise<WebEngineStatus> {
       await wasmModuleLoader.preloadCompleted();
       const imported = await import("../vendor/blender/web_engine.js") as unknown as { default: WasmFactory };
       const factory = imported.default;
-      const binary = await wasmModuleLoader.load("core-completed");
+      const binary = await wasmModuleLoader.loadDebug("debug-incremental");
       const initializedModule = await factory({ wasmBinary: binary });
       const initializedHandle = initializedModule._web_engine_create();
       if (initializedHandle <= 0) throw new Error("WebEngine handle creation failed");
diff --git a/web/tests/e2e/wasm-module-loading.spec.ts b/web/tests/e2e/wasm-module-loading.spec.ts
new file mode 100644
index 000000000..ea6ad73f2
--- /dev/null
+++ b/web/tests/e2e/wasm-module-loading.spec.ts
@@ -0,0 +1,28 @@
+import { expect, test } from "@playwright/test";
+
+test("preloads completed WASM and loads the debug module independently", async ({ page }) => {
+  await page.goto("/");
+  const result = await page.evaluate(async () => {
+    const { WebEngineClient } = await import("/src/engine-client/WebEngineClient.ts");
+    const client = new WebEngineClient({ timeoutMs: 60_000 });
+    try {
+      await client.init();
+      const before = await client.snapshot();
+      const pending = before.status;
+      const loaded = await client.loadDebugWasmModule("debug-incremental");
+      return {
+        pending,
+        loaded,
+        debug: loaded.find((module) => module.id === "debug-incremental"),
+        completed: loaded.filter((module) => module.lifecycle === "complete"),
+      };
+    }
+    finally { await client.shutdown(); }
+  });
+  expect(result.pending.ready).toBe(true);
+  expect(result.completed.length).toBeGreaterThan(0);
+  expect(result.completed.every((module) => module.status === "loaded")).toBe(true);
+  expect(result.debug?.status).toBe("loaded");
+  expect(result.debug?.lifecycle).toBe("debug");
+  expect(result.debug?.byteLength).toBeGreaterThan(0);
+});