docs: add npm 11 Electron setup steps to meshbay-client README

2026-08-22T09:09:22Z

npm >= 11 blocks install scripts by default. Document the approve-scripts + manual install + chrome-sandbox SUID steps. Co-Authored-By: Claude Opus 4.6

fix(client): the desktop client runs, and running it corrected three things

2026-08-18T08:30:59Z

Electron 42 / Chromium 148, launched under xvfb. The packaged interface mounts over `app://` with a secure context, `crypto.subtle` present, Argon2 WASM loaded, and no console errors. Three statements in the design were wrong, and only launching it found them. **A CSP in a `` tag silently drops `frame-ancestors`.** Chromium says so in the console. A policy carrying a directive that does nothing is worse than one without it, so the policy is sent as a header by the protocol handler — which is also the only thing serving the interface, so one source instead of two. **`secure: true` is not what makes the service worker register.** Chromium refuses a worker on a custom scheme whatever its privileges: "The URL protocol of the current origin ('app://meshbay') is not supported". The application has no service worker and needs none — it saves through a native dialog, which is the better of the two paths. `sw.js` stays in the package because the same files serve the browser, where it is one of only three ways to write a large file. What `secure: true` is actually for was measured at the same time: without it **the whole of `crypto.subtle` is undefined**. The first probe loaded a `data:` URL and every algorithm failed with TypeError, AES-GCM included — which is why the probe was rewritten before believing its answer. X25519 and Ed25519 are both present on Chromium 148, settling the version floor left open as O6. **The renderer cannot call the hub.** Its origin is `app://meshbay` and CORS refuses it. The hub has *no CORS middleware at all* — its API is reachable from no web origin whatever — and that is worth keeping. Widening it for `app://meshbay` would be worse than it looks: that origin is not a credential, since any Electron application can claim the same scheme and host name. So every hub call leaves from the main process, exactly as saving a file does, and it refuses any origin that is not the hub the user signed in to. `platform.apiFetch()` is `fetch` in a browser and the bridge in the application, so no caller has to know which it got. `transport.js` reaches it through a global because it is a classic script, not a module — the alternative was a second fetch path, which is how two callers of one hub start disagreeing about how to reach it. Verified from inside Electron: the main process gets 200 from /v1/hub/version, the renderer is refused by CORS, and **a script served by the hub is refused by the policy** — T3's mitigation demonstrated rather than asserted. Build note, written into the README because it will bite the next person: **Ubuntu 24.04's nodejs 18 cannot install Electron at all** — the download script `require()`s an ESM module, which Node gained in 22. Node 24 LTS, checksum-verified against nodejs.org, is what this was built with. package-lock.json is committed; builds use `npm ci`, not `npm install`. 799 tests pass, e2e.py still passes end to end. The session harness needed a platform stub: it lifts `hubFetch` out of app.js as text and runs it, so the adapter is now part of the environment it models. Co-Authored-By: Claude Opus 5

meshbay.git/packages/meshbay-client/README.md, branch 0.6

docs: add npm 11 Electron setup steps to meshbay-client README

fix(client): the desktop client runs, and running it corrected three things