fix(server): detect OpenCode version via spawn spec

packages/server/src/workspaces/runtime.ts

@@ -8,6 +8,8 @@ import { Logger } from "../logger"
 export const WINDOWS_CMD_EXTENSIONS = new Set([".cmd", ".bat"])
 export const WINDOWS_POWERSHELL_EXTENSIONS = new Set([".ps1"])
 
+const VERSION_REGEX = /([0-9]+\.[0-9]+\.[0-9A-Za-z.-]+)/
+
 export function buildSpawnSpec(binaryPath: string, args: string[]) {
   if (process.platform !== "win32") {
     return { command: binaryPath, args, options: {} as const }
@@ -40,6 +42,61 @@ export function buildSpawnSpec(binaryPath: string, args: string[]) {
   return { command: binaryPath, args, options: {} as const }
 }
 
+export function probeBinaryVersion(binaryPath: string): {
+  valid: boolean
+  version?: string
+  reported?: string
+  error?: string
+} {
+  if (!binaryPath) {
+    return { valid: false, error: "Missing binary path" }
+  }
+
+  const spec = buildSpawnSpec(binaryPath, ["--version"])
+
+  try {
+    const result = spawnSync(spec.command, spec.args, {
+      encoding: "utf8",
+      windowsVerbatimArguments: Boolean(
+        (spec.options as { windowsVerbatimArguments?: boolean }).windowsVerbatimArguments,
+      ),
+    })
+
+    if (result.error) {
+      return { valid: false, error: result.error.message }
+    }
+
+    if (result.status !== 0) {
+      const stderr = result.stderr?.trim()
+      const stdout = result.stdout?.trim()
+      const combined = stderr || stdout
+      const error = combined ? `Exited with code ${result.status}: ${combined}` : `Exited with code ${result.status}`
+      return { valid: false, error }
+    }
+
+    const stdoutLines = String(result.stdout ?? "")
+      .split(/\r?\n/)
+      .map((line) => line.trim())
+      .filter((line) => line.length > 0)
+    const stderrLines = String(result.stderr ?? "")
+      .split(/\r?\n/)
+      .map((line) => line.trim())
+      .filter((line) => line.length > 0)
+
+    // Prefer stdout; fall back to stderr (some tools report version there).
+    const reported = stdoutLines[0] ?? stderrLines[0]
+    if (!reported) {
+      return { valid: true }
+    }
+
+    const versionMatch = reported.match(VERSION_REGEX)
+    const version = versionMatch?.[1]
+    return { valid: true, version, reported }
+  } catch (error) {
+    return { valid: false, error: error instanceof Error ? error.message : String(error) }
+  }
+}
+
 const SENSITIVE_ENV_KEY = /(PASSWORD|TOKEN|SECRET)/i
 
 function redactEnvironment(env: Record<string, string | undefined>): Record<string, string | undefined> {