feat: add durable addressed registry publication

backend/test/workspace-fs-at-native.test.ts

@@ -0,0 +1,4 @@
+import { describe, expect, it } from "vitest";
+import { WorkspaceFsAtV1 } from "../src/workspaces/workspace-fs-at.js";
+import { mkdtempSync, mkdirSync, statSync } from "node:fs"; import { tmpdir } from "node:os"; import { join } from "node:path";
+describe("workspace fs-at seam",()=>{it("opens anchored directories and literal locks",()=>{const root=mkdtempSync(join(process.cwd(),"thoth-fsat-")); mkdirSync(join(root,"sessions"),{mode:0o700}); const fs=new WorkspaceFsAtV1(); const d=fs.openRoot(); const s=fs.openDirectoryAt(d,"private"); expect(s.stat().mode).toBeTruthy(); s.close(); d.close();});});