接续L4-TOOL-DB浏览器Worker边界

结论：浏览器 Tool DB Worker 传输层已接入并明确阻塞缺失的 Python/WASM runtime，未冒充 DB_PROGRAM 执行就绪。

wasm-port/tests/browser/tool_db_process_browser_smoke.html

@@ -9,6 +9,7 @@
   <script type="module">
     import {
       createLinuxCncToolDbProcessPort,
+      createLinuxCncToolDbBrowserWorkerAdapter,
       createToolDbProcessDiagnostics,
       createToolDbStorePaths,
       loadToolDbFile,
@@ -58,6 +59,32 @@
       assertEqual(planResult.status, "blocked_runtime_adapter_required", "contract-only plan status");
       assertEqual(planResult.tblFallbackSufficient, false, "tbl fallback guard");
 
+      const workerAdapter = createLinuxCncToolDbBrowserWorkerAdapter({
+        workerUrl: new URL("../../runtime/workers/tool-db-python-worker.js", import.meta.url),
+      });
+      const workerPort = createLinuxCncToolDbProcessPort({
+        dbProgramPath: "./db_nonran.py",
+        sourceFiles: [
+          "configs/sim/axis/db_demo/db_nonran.py",
+          "configs/sim/axis/db_demo/db.py",
+          "lib/python/tooldb.py",
+        ],
+        runtimeMode: workerAdapter.runtimeMode,
+        runtimeAdapter: workerAdapter,
+      });
+      const workerStart = await workerPort.start();
+      assertEqual(workerStart.runtimeMode, "browser-python-wasm-worker", "worker runtime mode");
+      assertEqual(workerStart.runtimeExecutionReady, false, "worker Python runtime readiness");
+      assertEqual(workerStart.status, "blocked_browser_python_wasm_runtime_missing", "worker Python runtime status");
+      const workerPlanResult = await workerPort.runTransactionPlan();
+      assertEqual(
+        workerPlanResult.status,
+        "blocked_browser_python_wasm_runtime_missing",
+        "worker plan blocked without Python/WASM runtime",
+      );
+      assertEqual(workerPlanResult.promotionAllowed, false, "worker promotion guard");
+      await workerPort.close();
+
       const transcript = [
         { direction: "read", line: "v2.1" },
         { direction: "write", line: "g" },