feat(desktop): support macOS cross-platform packaging (#1262)

* feat(desktop): support macOS cross-platform packaging

* fix(desktop): use releaseType instead of publishingType in electron-builder publish config

publishingType is not a valid electron-builder key; the correct GitHub
provider option is releaseType. The previous value was silently ignored,
causing uploads to be skipped and breaking auto-update.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(release): standardize artifact naming across desktop and CLI

Unified scheme: `multica-<kind>-<version>-<platform>-<arch>.<ext>` so a
filename alone reveals kind, version, platform, and CPU arch.

Desktop (apps/desktop/electron-builder.yml):
  mac     → multica-desktop-<v>-mac-<arch>.{dmg,zip}
  linux   → multica-desktop-<v>-linux-<arch>.{deb,AppImage}
    (fixes `\${name}` expanding the scoped `@multica/desktop` into a
    broken `@multica/desktop-*` filename path)
  windows → multica-desktop-<v>-windows-<arch>.exe

CLI (.goreleaser.yml):
  multica_<os>_<arch>.tar.gz → multica-cli-<v>-<os>-<arch>.tar.gz
  (adds `-cli` marker + version; switches `_` to `-` for consistency)

Matrix update in apps/desktop/scripts/package.mjs `--all-platforms`:
  - drop mac x64 (Intel not a target yet)
  - add linux arm64
  Final: mac arm64, win x64/arm64, linux x64/arm64.

Downstream updates so install paths match the new CLI names:
  - scripts/install.sh
  - scripts/install.ps1 (URL + checksum regex)
  - CLI_INSTALL.md

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(release): use multica_{os}_{arch} CLI archive naming

Standardize on the GoReleaser default 'multica_{os}_{arch}.{tar.gz|zip}'
asset names. Install scripts and the desktop CLI bootstrap now resolve
assets via checksums.txt so they work without hardcoding versions.

The Go self-update path queries the GitHub release API and accepts
either the new or legacy 'multica-cli-<version>-...' names so existing
releases keep updating cleanly.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(release): ship both legacy and versioned CLI archive names

GoReleaser now produces both 'multica_{os}_{arch}.{ext}' (legacy) and
'multica-cli-{version}-{os}-{arch}.{ext}' (versioned) archives in every
release. The legacy name keeps already-released CLIs self-updating; the
versioned name is what new clients should use going forward.

Self-update / install paths flipped to prefer the versioned name and
fall back to legacy:
  - server/internal/cli/update.go (multica update)
  - apps/desktop/src/main/cli-release-asset.ts (desktop CLI bootstrap)
  - scripts/install.sh, scripts/install.ps1 (fresh install)

Homebrew formula is pinned to the versioned archive via 'ids: [versioned]'.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(desktop): also build Linux .rpm packages

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* feat(release): build Linux/Windows Desktop installers in CI; detect Windows ARM64 in install.ps1

Address review feedback on PR #1262:

- .github/workflows/release.yml: add a 'desktop' job that runs after the
  CLI 'release' job and packages the Desktop installers for Linux
  (AppImage/deb/rpm) and Windows (NSIS) on x64 and arm64, then publishes
  them to the same GitHub Release via electron-builder. macOS Desktop
  continues to ship through the manual release-desktop skill so it can
  be signed and notarized with Apple Developer credentials.

- scripts/install.ps1: detect Windows ARM64 hosts via
  RuntimeInformation::OSArchitecture so the new windows-arm64 CLI
  archive is downloaded on ARM64 machines instead of always falling
  back to amd64.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fix(release): split Windows arm64 auto-update channel to avoid latest.yml collision

electron-builder's update metadata file is hardcoded to `latest.yml` for
Windows regardless of arch (only Linux gets an arch-suffixed name; see
app-builder-lib's getArchPrefixForUpdateFile). With two separate
electron-builder invocations for Windows x64 and arm64, both publish
`latest.yml` to the same GitHub Release and the second upload silently
overwrites the first — leaving one of the two architectures with auto-
update metadata pointing at the other arch's installer.

Route Windows arm64 to its own `latest-arm64` channel:

* scripts/package.mjs appends `-c.publish.channel=latest-arm64` only
  for the Windows arm64 invocation, so x64 keeps producing `latest.yml`
  and arm64 produces `latest-arm64.yml` alongside it.
* updater.ts pins `autoUpdater.channel = 'latest-arm64'` on Windows
  arm64 clients so they fetch the matching metadata file.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Devv <devv@Devvs-Mac-mini.local>
Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

.github/workflows/release.yml

@@ -44,3 +44,60 @@ jobs:
         env:
           GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           HOMEBREW_TAP_GITHUB_TOKEN: ${{ secrets.HOMEBREW_TAP_GITHUB_TOKEN }}
+
+  # Build the Desktop installers for Linux and Windows and upload them to
+  # the GitHub Release that the `release` job above just published. macOS
+  # Desktop continues to ship via the manual `release-desktop` skill so it
+  # can be signed + notarized with Apple Developer credentials that are
+  # not (yet) wired into CI.
+  desktop:
+    needs: release
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            target: linux
+          - os: windows-latest
+            target: win
+    runs-on: ${{ matrix.os }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - name: Install rpmbuild (Linux)
+        if: matrix.target == 'linux'
+        run: sudo apt-get update && sudo apt-get install -y rpm
+
+      - name: Setup Go
+        uses: actions/setup-go@v5
+        with:
+          go-version-file: server/go.mod
+          cache-dependency-path: server/go.sum
+
+      - name: Setup pnpm
+        uses: pnpm/action-setup@v4
+
+      - name: Setup Node
+        uses: actions/setup-node@v4
+        with:
+          node-version: 22
+          cache: pnpm
+
+      - name: Install dependencies
+        run: pnpm install --frozen-lockfile
+
+      - name: Package Desktop installers (${{ matrix.target }})
+        working-directory: apps/desktop
+        env:
+          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # electron-builder's GitHub publisher reads this:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          # Disable code signing on Linux/Windows for now — the public
+          # release is unsigned for these platforms, the CLI carries the
+          # trust boundary. Set CSC_LINK in repo secrets to enable
+          # Windows signing later.
+          CSC_IDENTITY_AUTO_DISCOVERY: "false"
+        run: node scripts/package.mjs --${{ matrix.target }} --x64 --arm64 --publish always