fix(#2849): resolve platform binaries using current package name

The installer wrapper and postinstall script still hardcoded the old
oh-my-opencode-* platform package family. When users installed the renamed
npm package oh-my-openagent (for example via npx oh-my-openagent install on
WSL2/Linux), the main package installed correctly but the wrapper looked for
nonexistent optional binaries like oh-my-opencode-linux-x64.

Fix:
- derive packageBaseName from package.json at runtime in wrapper/postinstall
- thread packageBaseName through platform package candidate resolution
- keep legacy oh-my-opencode default as fallback
- add regression test for renamed package family

bin/oh-my-opencode.js

@@ -71,9 +71,19 @@ function getSignalExitCode(signal) {
   return 128 + (signalCodeByName[signal] ?? 1);
 }
 
+function getPackageBaseName() {
+  try {
+    const packageJson = JSON.parse(readFileSync(new URL("../package.json", import.meta.url), "utf8"));
+    return packageJson.name || "oh-my-opencode";
+  } catch {
+    return "oh-my-opencode";
+  }
+}
+
 function main() {
   const { platform, arch } = process;
   const libcFamily = getLibcFamily();
+  const packageBaseName = getPackageBaseName();
   const avx2Supported = supportsAvx2();
   
   let packageCandidates;
@@ -83,6 +93,7 @@ function main() {
       arch,
       libcFamily,
       preferBaseline: avx2Supported === false,
+      packageBaseName,
     });
   } catch (error) {
     console.error(`\noh-my-opencode: ${error.message}\n`);

bin/platform.js

@@ -3,11 +3,11 @@
 
 /**
  * Get the platform-specific package name
- * @param {{ platform: string, arch: string, libcFamily?: string | null }} options
+ * @param {{ platform: string, arch: string, libcFamily?: string | null, packageBaseName?: string }} options
  * @returns {string} Package name like "oh-my-opencode-darwin-arm64"
  * @throws {Error} If libc cannot be detected on Linux
  */
-export function getPlatformPackage({ platform, arch, libcFamily }) {
+export function getPlatformPackage({ platform, arch, libcFamily, packageBaseName = "oh-my-opencode" }) {
   let suffix = "";
   if (platform === "linux") {
     if (libcFamily === null || libcFamily === undefined) {
@@ -23,13 +23,13 @@ export function getPlatformPackage({ platform, arch, libcFamily }) {
   
   // Map platform names: win32 -> windows (for package name)
   const os = platform === "win32" ? "windows" : platform;
-  return `oh-my-opencode-${os}-${arch}${suffix}`;
+  return `${packageBaseName}-${os}-${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 });
+/** @param {{ platform: string, arch: string, libcFamily?: string | null, preferBaseline?: boolean, packageBaseName?: string }} options */
+export function getPlatformPackageCandidates({ platform, arch, libcFamily, preferBaseline = false, packageBaseName = "oh-my-opencode" }) {
+  const primaryPackage = getPlatformPackage({ platform, arch, libcFamily, packageBaseName });
+  const baselinePackage = getBaselinePlatformPackage({ platform, arch, libcFamily, packageBaseName });
 
   if (!baselinePackage) {
     return [primaryPackage];
@@ -38,18 +38,18 @@ export function getPlatformPackageCandidates({ platform, arch, libcFamily, prefe
   return preferBaseline ? [baselinePackage, primaryPackage] : [primaryPackage, baselinePackage];
 }
 
-/** @param {{ platform: string, arch: string, libcFamily?: string | null }} options */
-function getBaselinePlatformPackage({ platform, arch, libcFamily }) {
+/** @param {{ platform: string, arch: string, libcFamily?: string | null, packageBaseName?: string }} options */
+function getBaselinePlatformPackage({ platform, arch, libcFamily, packageBaseName = "oh-my-opencode" }) {
   if (arch !== "x64") {
     return null;
   }
 
   if (platform === "darwin") {
-    return "oh-my-opencode-darwin-x64-baseline";
+    return `${packageBaseName}-darwin-x64-baseline`;
   }
 
   if (platform === "win32") {
-    return "oh-my-opencode-windows-x64-baseline";
+    return `${packageBaseName}-windows-x64-baseline`;
   }
 
   if (platform === "linux") {
@@ -61,10 +61,10 @@ function getBaselinePlatformPackage({ platform, arch, libcFamily }) {
     }
 
     if (libcFamily === "musl") {
-      return "oh-my-opencode-linux-x64-musl-baseline";
+      return `${packageBaseName}-linux-x64-musl-baseline`;
     }
 
-    return "oh-my-opencode-linux-x64-baseline";
+    return `${packageBaseName}-linux-x64-baseline`;
   }
 
   return null;

bin/platform.test.ts

@@ -190,6 +190,21 @@ describe("getPlatformPackageCandidates", () => {
     ]);
   });
 
+
+
+  test("supports renamed package family via packageBaseName override", () => {
+    // #given Linux x64 with glibc and renamed package base
+    const input = { platform: "linux", arch: "x64", libcFamily: "glibc", packageBaseName: "oh-my-openagent" };
+
+    // #when getting package candidates
+    const result = getPlatformPackageCandidates(input);
+
+    // #then returns renamed package family candidates
+    expect(result).toEqual([
+      "oh-my-openagent-linux-x64",
+      "oh-my-openagent-linux-x64-baseline",
+    ]);
+  });
   test("returns only one candidate for ARM64", () => {
     // #given non-x64 platform
     const input = { platform: "linux", arch: "arm64", libcFamily: "glibc" };