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');

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

@@ -0,0 +1,63 @@
+import assert from 'node:assert/strict';
+import { execFileSync, spawnSync } from 'node:child_process';
+import fs from 'node:fs';
+import os from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import { fileURLToPath } from 'node:url';
+
+const script = fileURLToPath(new URL('./finalize-latest-yml.mjs', import.meta.url));
+
+const manifest = (architecture) => `version: 1.2.3
+files:
+  - url: OpenChamber-1.2.3-win-${architecture}.exe
+    sha512: ${architecture}-checksum
+    size: 123
+releaseDate: '2026-07-30T00:00:00.000Z'
+`;
+
+const createFixture = ({ includeArm64 = true } = {}) => {
+  const root = fs.mkdtempSync(path.join(os.tmpdir(), 'openchamber-latest-yml-'));
+  const artifacts = path.join(root, 'artifacts');
+  const output = path.join(root, 'output');
+  fs.mkdirSync(path.join(artifacts, 'latest-yml-x86_64-pc-windows-msvc'), { recursive: true });
+  fs.writeFileSync(path.join(artifacts, 'latest-yml-x86_64-pc-windows-msvc', 'latest.yml'), manifest('x64'));
+  if (includeArm64) {
+    fs.mkdirSync(path.join(artifacts, 'latest-yml-aarch64-pc-windows-msvc'), { recursive: true });
+    fs.writeFileSync(path.join(artifacts, 'latest-yml-aarch64-pc-windows-msvc', 'latest.yml'), manifest('arm64'));
+  }
+  fs.mkdirSync(output);
+  return { root, artifacts, output };
+};
+
+const environment = ({ artifacts, output }) => ({
+  ...process.env,
+  LATEST_YML_DIR: artifacts,
+  RUNNER_TEMP: output,
+  GH_REPO: 'openchamber/openchamber',
+  OPENCHAMBER_VERSION: '1.2.3',
+});
+
+test('writes separate x64 and ARM64 Windows update channels', (context) => {
+  const fixture = createFixture();
+  context.after(() => fs.rmSync(fixture.root, { recursive: true, force: true }));
+
+  execFileSync(process.execPath, [script], { env: environment(fixture) });
+
+  const x64 = fs.readFileSync(path.join(fixture.output, 'latest.yml'), 'utf8');
+  const arm64 = fs.readFileSync(path.join(fixture.output, 'latest-arm64.yml'), 'utf8');
+  assert.match(x64, /win-x64\.exe/);
+  assert.doesNotMatch(x64, /win-arm64\.exe/);
+  assert.match(arm64, /win-arm64\.exe/);
+  assert.doesNotMatch(arm64, /win-x64\.exe/);
+});
+
+test('fails instead of publishing an incomplete Windows channel set', (context) => {
+  const fixture = createFixture({ includeArm64: false });
+  context.after(() => fs.rmSync(fixture.root, { recursive: true, force: true }));
+
+  const result = spawnSync(process.execPath, [script], { env: environment(fixture), encoding: 'utf8' });
+
+  assert.notEqual(result.status, 0);
+  assert.match(result.stderr, /Both x64 and arm64 Windows update manifests are required/);
+});

packages/electron/scripts/prepare-opencode-cli.mjs

@@ -47,7 +47,17 @@ const artifactForPlatform = (platform, targetArchitecture) => {
     if (arch === 'x64') return { name: 'opencode-darwin-x64-baseline.zip', binary: 'opencode' };
   }
   if (platform === 'win32') {
-    if (arch === 'arm64') return { name: 'opencode-windows-arm64.zip', binary: 'opencode.exe' };
+    // TEMPORARY WORKAROUND — Windows ARM64: native opencode.exe fails with a Bun
+    // FFI/TinyCC dlopen error (https://github.com/anomalyco/opencode/issues/19130).
+    // Bundle x64-baseline instead (runs under x64 emulation); OpenCode self-upgrade
+    // is disabled elsewhere so it can't overwrite with the broken ARM64 build.
+    // Remove this block and restore the original below when the upstream issue
+    // is resolved.
+    // --- ORIGINAL (restore when ARM64 is fixed) ---
+    // if (arch === 'arm64') return { name: 'opencode-windows-arm64.zip', binary: 'opencode.exe' };
+    // if (arch === 'x64') return { name: 'opencode-windows-x64-baseline.zip', binary: 'opencode.exe' };
+    // --- END ORIGINAL ---
+    if (arch === 'arm64') return { name: 'opencode-windows-x64-baseline.zip', binary: 'opencode.exe' };
     if (arch === 'x64') return { name: 'opencode-windows-x64-baseline.zip', binary: 'opencode.exe' };
   }
   if (platform === 'linux') {