fix(desktop): move settings-store writes off the main thread

CHANGELOG.md

@@ -9,6 +9,15 @@ file is the human-readable summary of what changed and why.
 
 ### Desktop / Web UI
 
+- **A stalling disk can no longer freeze the app** — saving any setting
+  (window layout, server list, sandbox folders) used to write to disk
+  synchronously on the app's main thread. If the operating system's disk
+  journal stalled at that moment — observed on a machine whose NVMe drive
+  dropped a write during a power-state transition — the entire app froze
+  beyond even quitting, and had to be killed. Settings now save in the
+  background: the app stays responsive through a disk stall and the save
+  lands when the disk recovers. On quit and relaunch, pending saves get a
+  bounded window to finish so a wedged disk cannot hang shutdown either.
 - **Sandboxes can mount more folders after creation** — a sandbox used to be
   locked to the one project folder chosen when it was created. Each sandbox
   now has a **Folders…** entry in its menu (Settings → Servers) to mount

DIVERGENCES.md

@@ -195,6 +195,7 @@ from the squash message first, or use a plain merge.
 | `packages/desktop/src/renderer/index.tsx` | Calls `installConsoleFormatting()` (fork-only `./console-format`) before anything else logs. | `spyRendererConsole` receives Chromium's flattened console-message string, so any renderer `console.*` with an object argument reached the terminal and the exported debug logs as `[object Object]`; the wrapper serializes structured arguments (Error-aware, circular-safe, truncated) at the source. | Keep the import and call; take upstream's surrounding entry changes. |
 | `packages/desktop/src/main/updater.ts` | `autoUpdater.allowDowngrade` `true` → `false`. | Upstream's `true` is safe against immutable GitHub release tags. The fork's feed is a mutable bucket path, where re-uploading or failing to replace a stale `latest.yml` would actively downgrade every client on the next 10-minute poll. | Keep `false`; take upstream's other updater settings. `channel = "latest"` and `allowPrerelease = false` stay as upstream has them — the first must match `publish.channel` in `electron-builder.config.ts`, the second is inert for the `generic` provider (it only steers GitHub tag resolution). |
 | Dual-path WSL install: `packages/desktop/src/main/wsl/{runtime,servers}.ts` | `runtime.ts`: three internals gain `export` (`runPowerShell`, `runInteractiveCommand`, `resolveSystem32Command`) — no behavior change. `servers.ts`: the `install-wsl` job calls `installWslRuntimeDualPath` and the `install-distro` job calls `installWslDistroDualPath` (both from the fork-only `install-bundle.ts`, which holds all new logic) instead of `installWslRuntimeElevated` / `installWslDistro` directly; both return the same `WslCommandResult` shape, so the surrounding job/error handling is untouched. | The customer fleet sits behind whitelist-only proxies that cannot reach Microsoft's servers. The dual path downloads the pinned bundle (`wsl.zip`: runtime MSI + Ubuntu-24.04 image) from the codev storage host, enables VirtualMachinePlatform via offline dism + installs the MSI behind one UAC prompt, and falls back to upstream's `wsl --install` / `--web-download` paths only when the bundle cannot be *obtained* — a completed-but-failed elevated install is returned as-is, never retried behind a second UAC prompt. | Keep the two call swaps and the three `export` keywords; take upstream's surrounding changes. If upstream reworks `installWslRuntimeElevated` / `installWslDistro`, keep them exported from `runtime.ts` — `install-bundle.ts` calls them as the fallback path. |
+| Async settings stores: `packages/desktop/src/main/{store,index}.ts`, `packages/desktop/package.json` | `store.ts` no longer uses electron-store: `getStore` now returns the fork-only `store-file.ts` store — in-memory state, flushed write-behind through `store-writer.ts`'s serialized latest-wins async atomic writer (temp → fsync → rename via `fs.promises`, so the fsync runs on the libuv threadpool). Adds `flushStoreWrites(timeoutMs)`; `removeStoreFile`/`removeStoreFileIfEmpty` discard/flush the writer around the delete so a late flush cannot resurrect the file. `index.ts`: `stopSidecars` awaits `flushStoreWrites(1500)`. `package.json`: the `electron-store` dependency is removed. On-disk format is unchanged (flat keys, tab-indented JSON, no extension) — existing files load as-is; a corrupt file now starts empty with a logged error instead of throwing from every accessor. | conf v15's `store.set` is a synchronous fsync on the Electron main thread, and one of those parked the whole app in uninterruptible disk sleep (kernel journal stall + lost ext4 fast-commit wakeup, observed live during a sandbox mount-apply restart): event loop dead, IPC dead, quit impossible. conf also rereads the file on every access, which makes write-behind unsound with the stock class (a set on one key reads a stale file and drops a still-queued update), so the storage layer had to be replaced rather than patched. | Keep the fork store; take upstream's surrounding changes. If upstream adds electron-store options (schema, migrations, dot-notation) or new store call sites, extend `store-file.ts` to match — its API is the superset the desktop actually uses (`get/set/has/delete/clear/store/path`). Do not reintroduce a synchronous write path on the main thread. |
 | Desktop sandbox wiring: `packages/desktop/src/main/{index,store-keys}.ts`, `packages/desktop/package.json` | Hooks the fork-only `src/main/sandbox/{bundle,controller,ipc}.ts` modules into startup: `index.ts` constructs the sandbox controller beside the WSL servers controller, adds `sandboxes.stopAll()` to `stopSidecars`, registers the `sandbox-*` IPC channels next to the WSL ones, and calls `sandboxes.initialize()` (all platforms) once the local server is ready; `store-keys.ts` gains `SANDBOXES_KEY = "sandboxes"`; `package.json` gains the `@codev/sandbox` and `@codev/gateway` workspace devDependencies (bundled into the main process by electron-vite, so not runtime dependencies; gateway supplies the sandbox egress broker's credentials and config fragment). | The desktop app is where sandboxes are created and run; `createSandboxController` generalizes the proven WSL-servers controller pattern to the per-platform `@codev/sandbox` providers (macOS vz / Windows wsl / Linux bwrap). | Keep the wiring lines and take upstream's surrounding changes; they are additive and order-insensitive apart from `initialize()` needing the local server ready first. Do not rename the `sandbox-*` channels or the `sandboxes` store key — preload/renderer and persisted sandbox configs depend on them. |
 | Desktop sandbox renderer slice: `packages/app/package.json`, `packages/app/src/{index.ts,app.tsx}`, `packages/app/src/context/{platform,server}.tsx`, `packages/app/src/components/{settings-v2/servers.tsx,dialog-select-server.tsx}`, `packages/app/src/wsl/settings.tsx`, `packages/app/src/i18n/{en,es}.ts`, `packages/desktop/src/preload/{index,types}.ts`, `packages/desktop/src/renderer/index.tsx` | Surfaces the fork-only sandbox modules (`packages/app/src/sandbox/*`, `packages/desktop/src/renderer/sandbox/*`) in the UI: app `package.json` exports `./sandbox/types` (mirror of `./wsl/types`); `index.ts` re-exports `useSandboxes` + the sandbox types; `app.tsx` mounts `SandboxesProvider` inside `WslServersProvider`; `platform.tsx` gains optional `sandboxes?: SandboxesPlatform`; `server.tsx` adds the third `ServerConnection.Sidecar` variant `{ variant: "sandbox"; name; projectDir?; mounts? }` with key `sandbox:<name>` (`projectDir` is the host folder mounted into the guest and `mounts` the extra host folders with their resolved guest paths — the guest only ever sees its own mount points, so this is the only way the app can name a sandbox's projects after the folders it works on); `settings-v2/servers.tsx` filters sandbox rows out of the generic list and renders `SandboxServerSettings` beside the WSL section; `dialog-select-server.tsx` `handleRemove` routes `sandbox:` keys to `platform.sandboxes.remove` (like `wsl:` keys) and moves the `tabs.removeServer(key)` + `server.remove(key)` pair *above* both awaited platform removals; `wsl/settings.tsx` `AddServerMenu` shows the menu when either wslServers or sandboxes exist and gains an "Add sandbox" item; i18n gains the `sandbox.*` key family (including the optional per-sandbox CPU/memory fields, macOS-only since only the vz backend applies them; `sandbox.add.projectDirHint`, the standing explanation above the folder field; and the `sandbox.mounts.*` family for the manage-folders dialog that adds/removes extra mounts on an existing sandbox); preload exposes `api.sandboxes` over the `sandbox-*` channels and `renderer/index.tsx` wires the platform api, loading gate, ready-connection list, and the `startupServer` fallback (fork-only wrapper that validates `sandbox:` default keys the way `availableStartupServer` validates `wsl:` ones). | Ready sandboxes must appear as first-class servers and be manageable from settings; the slice mirrors the WSL vertical exactly so upstream conflicts resolve the same way in both. Removing a server destroys a disk and takes seconds, and the connection leaves the list the moment it finishes, so the tab cleanup has to happen before the await rather than after it. | Keep every listed edit; take upstream's surrounding changes. If upstream adds a `Sidecar` variant or reworks `AddServerMenu`, re-apply the sandbox variant/menu item on top. The `sandbox:<name>` key format is persisted as the default-server key and as `config.id` in the main-process store — never change one side alone. Keep the tab cleanup ahead of the platform removals in `handleRemove`; if upstream reorders it back, re-apply. |