[Bug]: Windows installer writes 14,687 files to ship 20 native binaries, costing install time and ~6s of cold start #5876

Before submitting

• I searched existing issues and did not find a duplicate.
• I included enough detail to reproduce or investigate the problem.

Area

Build, CI, or release tooling

Steps to reproduce

1. pnpm dist:desktop:win on Windows 11 x64 (measured at main @ ba9c9ae; re-checked at 02f4ce5)
2. Count the files in the NSIS payload:
   7z e release/T3-Code-*-x64.exe '$PLUGINSDIR/app-64.7z' then 7z l -slt app-64.7z
3. Install the result, and time the first launch

Expected behavior

The installer writes roughly the number of files the app actually needs on disk, and a cold start is not dominated by module loading.

Actual behavior

The Windows installer writes 14,687 files. 13,875 of them are loose node_modules files under app.asar.unpacked. Only 20 are native .node binaries. For contrast, the entire Electron runtime — several hundred MB — is 22 files, because it stays inside the archive.

The cause is WINDOWS_ASAR_UNPACK in scripts/build-desktop-artifact.ts:

export const WINDOWS_ASAR_UNPACK = ["apps/server/dist/**", "**/node_modules/**"] as const;

That blanket unpack is load-bearing today: the CLI bundle externalizes its runtime dependencies, and the WSL backend launches plain wsl.exe -- node, which cannot read inside an asar. So every external dep has to be a real file.

This costs twice:

• Install. NSIS install time tracks file count, not bytes.
• Cold start. Each of those files is a separate open/stat/scan the first time the server runs after an install — exactly when the OS file cache is cold and the on-access scanner is not.

Inverting the bundler's rule — bundle everything except what genuinely cannot be inlined (native addons, the JS wrappers that dlopen them, and the Bun-only entry points resolving bun:*) — lets asarUnpack narrow to that set:

Cold start improves by the same mechanism. Extracting each build's payload to a fresh directory (so the files have never been read) and booting the server, alternating run order between builds so cache and scanner state could not favour either one:

The main window is not created until the backend answers HTTP, so that ~6s comes straight off a cold launch.

Second, unrelated issue in the same area. installWindowsEnvironment in apps/desktop/src/shell/DesktopShellEnvironment.ts spawns PowerShell twice in series at offset 0 of desktop.startup, before anything else runs. The two probes are independent — only their results are combined. Traces over this code path measured them at 2718ms then 2066ms: the whole 4.8s startup span, of which desktop.bootstrap is ~30ms.

Why this is Windows-only: asarUnpack is gated to platform === "win". macOS and Linux use electron-builder's smart unpack and stay packed, so none of this is visible there.

Impact

Major degradation or frequent failure

Version or commit

main @ ba9c9ae (re-verified against 02f4ce5)

Environment

Windows 11 Enterprise 26220, x64, Node 24.18.0, pnpm 11.10.0, electron-builder win/nsis

Workaround

None from the user side; it's in the packaging config.