feat: add Windows ARM64 support with x64-baseline CLI workaround (#2537)

* feat: add Windows ARM64 support with x64-baseline CLI workaround

Windows ARM64 native opencode.exe fails with a Bun FFI/TinyCC dlopen
error (anomalyco/opencode#19130). As a temporary workaround:

- Bundle x64-baseline OpenCode CLI on ARM64 instead of native ARM64
  (prepare-opencode-cli.mjs, env-runtime.js)
- Disable OpenCode self-upgrade on ARM64 in server, VS Code, and UI
  (upgrade-capability.js, opencode-upgrade-runtime.ts, useUIStore.ts,
  OpenCodeCliSettings.tsx, search.ts, SettingsView.tsx, platform.ts)
- Add ARM64 Windows cross-compile builds to release and smoke workflows
  (release.yml, release-desktop-smoke.yml)
- Refactor Windows latest.yml to use combine-electron-manifests pattern
  matching macOS, since two arches now produce per-arch manifests

The CI ARM64 build itself is permanent; only the x64-baseline CLI
bundling and upgrade disablement are temporary and should be reverted
when the upstream issue is resolved.

* fix(desktop): select Windows updater by architecture

---------

Co-authored-by: Bohdan Triapitsyn <artmore@protonmail.com>

packages/electron/scripts/finalize-latest-yml.mjs

@@ -76,14 +76,11 @@ const output = {};
 
 const winX64 = await read('latest-yml-x86_64-pc-windows-msvc', 'latest.yml');
 const winArm64 = await read('latest-yml-aarch64-pc-windows-msvc', 'latest.yml');
-if (winX64 || winArm64) {
-  const base = winArm64 || winX64;
-  output['latest.yml'] = serialize({
-    version: base.version,
-    files: [...(winArm64?.files || []), ...(winX64?.files || [])],
-    releaseDate: base.releaseDate,
-  });
+if (!winX64 || !winArm64) {
+  throw new Error('Both x64 and arm64 Windows update manifests are required');
 }
+output['latest.yml'] = serialize(winX64);
+output['latest-arm64.yml'] = serialize(winArm64);
 
 const macX64 = await read('latest-yml-x86_64-apple-darwin', 'latest-mac.yml');
 const macArm64 = await read('latest-yml-aarch64-apple-darwin', 'latest-mac.yml');