Feature request: official Windows x64 build

[whiteworthy]

The problem

T4 Code currently has no Windows package. I tested current main at 0eb0749 on Windows 11 x64 with Node 24.13.1, pnpm 11.10.0, and Bun 1.3.14:

• pnpm install --frozen-lockfile, build:web, and build:desktop succeeded.
• build:host produced dist/t4-host.exe.
• The Electron dev app launched.
• A direct Electron Builder invocation produced and launched an unsigned NSIS artifact, T4-Code-0.1.30-win-x64.exe.

The supported path is blocked by a few concrete gaps:

• Packaging config, preflight, and packaged runtime lookup require extensionless t4-host instead of t4-host.exe.
• run-electron-builder.mjs spawns the POSIX .bin/electron-builder shim, which returns ENOENT on Windows instead of resolving .cmd.
• win32 is reported as Linux, including in the update adapter.
• Local IPC and service management support only Unix sockets plus launchd/systemd.
• With normal Windows core.autocrlf=true, the byte-level provenance check reports checksum mismatches; LF-normalizing a sampled failure reproduced the committed checksum.
• The release workflow and exact asset list have no Windows lane.

What you'd like

Please add an official Windows x64 build, ideally in two stages:

1. Remote client first: a repeatable package:win command producing NSIS or ZIP, proper win32 handling, platform-aware executable paths, safe update behavior, and a native build/launch/pairing smoke. Local-host controls can clearly report unsupported.
2. Local host later: secure Windows IPC, per-user supervision, Windows path/ACL handling, and a verified Windows OMP authority/runtime path.

What you do instead today (optional)

Direct Electron Builder can produce a remote-client proof build, but it bypasses preflight, omits t4-host, uses the default icon, and is not a supported release path.