cache platform binary in postinstall for faster startup (#14396)

packages/opencode/bin/opencode

@@ -25,6 +25,11 @@ if (envPath) {
 const scriptPath = fs.realpathSync(__filename)
 const scriptDir = path.dirname(scriptPath)
 
+const cached = path.join(scriptDir, ".opencode")
+if (fs.existsSync(cached)) {
+  run(cached)
+}
+
 const platformMap = {
   darwin: "darwin",
   linux: "linux",

packages/opencode/script/postinstall.mjs

@@ -106,11 +106,15 @@ async function main() {
       return
     }
 
-    // On non-Windows platforms, just verify the binary package exists
-    // Don't replace the wrapper script - it handles binary execution
     const { binaryPath } = findBinary()
-    console.log(`Platform binary verified at: ${binaryPath}`)
-    console.log("Wrapper script will handle binary execution")
+    const target = path.join(__dirname, "..", "bin", ".opencode")
+    if (fs.existsSync(target)) fs.unlinkSync(target)
+    try {
+      fs.linkSync(binaryPath, target)
+    } catch {
+      fs.copyFileSync(binaryPath, target)
+    }
+    fs.chmodSync(target, 0o755)
   } catch (error) {
     console.error("Failed to setup opencode binary:", error.message)
     process.exit(1)