## Summary

Adds `.msi` as a `deno desktop` output format, alongside the existing
`.dmg`/`.AppImage` and the `.deb`/`.rpm` formats added in #35296. As
with those, the format is chosen by the `--output` extension (or the
per-platform `output` key in the `desktop` block of `deno.json` — whose
Windows description already documented `MyApp.msi`); the driver strips
the extension, builds the intermediate Windows app dir, then wraps it in
an MSI.

The MSI database is authored entirely in pure Rust via the
[`msi`](https://crates.io/crates/msi) crate, with the file payload
stored in an embedded MSZIP cabinet
([`cab`](https://crates.io/crates/cab) crate), so it **cross-compiles
from any host** — only the *target* must be Windows (gated like
`.deb`/`.rpm` are gated on a Linux target). The app installs per-machine
under `ProgramFiles64Folder\<AppName>\`, mirroring the staged app-dir
tree exactly (nested directories like CEF's `locales/` are preserved);
uninstall removes it.

```
%ProgramFiles%\<AppName>\
  <AppName>.bat          (launcher)
  laufey.exe             (CEF backend)
  libcef.dll, ...        (CEF support files)
  denort.dll             (compiled runtime + user code)
  ...                    (nested dirs preserved)
```

### Notable choices
- **Deterministic GUIDs** — `ProductCode`, `UpgradeCode`, the package
code, and per-component GUIDs are derived via UUIDv5 from the app
identity (`--identifier`), so identical inputs produce an identical
installer (matching the `source_date(0)` / `mtime: 0` reproducibility of
the `.rpm`/`.deb`/AppImage paths) and the `UpgradeCode` is stable across
versions.
- **Directory/Component model** — one `Component` per install directory
(a file's directory is carried by its component), `KeyPath` = the first
file in that directory, components flagged 64-bit
(`msidbComponentAttributes64bit`). A single `Feature` ties them
together.
- **Embedded cabinet** — one MSZIP folder holding every file named by
its MSI `File` key, referenced by `Media.Cabinet = #appcab`. Summary
stream marks the source compressed with long file names (`x64;1033` /
`Arm64;1033` template).
- **No new config fields** — metadata is derived from the staged app-dir
name, `--identifier`, and the default `1.0.0` version that matches the
macOS bundle.

### Metadata
Derived from existing config (app-dir name → `ProductName`,
`--identifier` → GUID seed, default `1.0.0` version). Help text for
`--output` now lists `MyApp.msi`.

## Why
This rounds out the desktop installer story for Windows — `.msi` was
explicitly left out of the original desktop PR (#33441). `.msi` is what
most Windows users/IT deployments install through.

## Tests
Pure-Rust unit tests (cross-platform): triple→arch mapping,
deterministic+valid GUID derivation, 8.3 short-name minting, and a full
`create_windows_msi` round-trip that parses the produced MSI back and
asserts the `Property`/`Directory`/`File`/`Component`/`Media` tables,
the 1..N file sequence, the two-component layout for a nested dir, and
that a file's bytes round-trip out of the embedded cabinet. All pass;
clippy clean.

As with `.deb`/`.rpm`, the matching-OS integration check (install /
launch / upgrade / uninstall on a real Windows box) can't run in the
cross-platform unit suite. Major-upgrade automation (an `Upgrade` table
+ `RemoveExistingProducts`) is intentionally left as a follow-up.

## New dependencies
`msi = "0.10.0"` and `cab = "0.6.0"` (both pure Rust). Also enables the
`v5` feature on the existing `uuid` dep.

Closes #35377
Ref mdsteele/rust-msi#59
Closes denoland/divybot#582

---------

Co-authored-by: divybot <[email protected]>
Co-authored-by: Divy Srivastava <[email protected]>