fix(ci): add baseline CPU variant binaries for legacy hardware support

Closes #2121

bin/platform.js

@@ -26,6 +26,50 @@ export function getPlatformPackage({ platform, arch, libcFamily }) {
   return `oh-my-opencode-${os}-${arch}${suffix}`;
 }
 
+/** @param {{ platform: string, arch: string, libcFamily?: string | null, preferBaseline?: boolean }} options */
+export function getPlatformPackageCandidates({ platform, arch, libcFamily, preferBaseline = false }) {
+  const primaryPackage = getPlatformPackage({ platform, arch, libcFamily });
+  const baselinePackage = getBaselinePlatformPackage({ platform, arch, libcFamily });
+
+  if (!baselinePackage) {
+    return [primaryPackage];
+  }
+
+  return preferBaseline ? [baselinePackage, primaryPackage] : [primaryPackage, baselinePackage];
+}
+
+/** @param {{ platform: string, arch: string, libcFamily?: string | null }} options */
+function getBaselinePlatformPackage({ platform, arch, libcFamily }) {
+  if (arch !== "x64") {
+    return null;
+  }
+
+  if (platform === "darwin") {
+    return "oh-my-opencode-darwin-x64-baseline";
+  }
+
+  if (platform === "win32") {
+    return "oh-my-opencode-windows-x64-baseline";
+  }
+
+  if (platform === "linux") {
+    if (libcFamily === null || libcFamily === undefined) {
+      throw new Error(
+        "Could not detect libc on Linux. " +
+        "Please ensure detect-libc is installed or report this issue."
+      );
+    }
+
+    if (libcFamily === "musl") {
+      return "oh-my-opencode-linux-x64-musl-baseline";
+    }
+
+    return "oh-my-opencode-linux-x64-baseline";
+  }
+
+  return null;
+}
+
 /**
  * Get the path to the binary within a platform package
  * @param {string} pkg Package name