fix: address Copilot review round 1 (#2333)

A runner that threw ETIMEDOUT landed in the catch and read as
unavailable, bypassing the split the previous commit added. The thrown
error is now normalized onto the `{ error }` path so the timeout check
covers both shapes; a test pins the thrown case.

Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PsmUAZ6aLUAFqenjJKSSRp
Signed-off-by: cliffhall <cliff@futurescale.com>

scripts/lib/pty.mjs

@@ -165,9 +165,12 @@ export function probeScriptVersion(
   let r;
   try {
     r = runner("script", ["--version"]);
-  } catch {
-    // A runner that throws outright (injected, or a future spawn shape).
-    return { available: false, output: "" };
+  } catch (err) {
+    // A runner that throws outright (injected, or a future spawn shape) is
+    // normalized onto the same path as one that returns `{ error }`, so the
+    // timeout check below applies to both shapes — a thrown ETIMEDOUT must not
+    // slip back into "unavailable" (Copilot, #2333).
+    r = { error: err };
   }
   if (r?.error?.code === "ETIMEDOUT") {
     throw new Error(

scripts/lib/pty.test.mjs

@@ -189,6 +189,15 @@ test("probeScriptVersion throws on a timed-out probe instead of reporting no scr
       probeScriptVersion(() => ({ error: timedOut, stdout: "", stderr: "" })),
     new RegExp(`did not exit within ${SCRIPT_PROBE_TIMEOUT_MS}ms`),
   );
+  // A runner that THROWS the same error is normalized onto the same path — the
+  // `catch` must not quietly turn a thrown ETIMEDOUT back into "unavailable".
+  assert.throws(
+    () =>
+      probeScriptVersion(() => {
+        throw timedOut;
+      }),
+    /did not exit within/,
+  );
   // And it reaches the caller: resolvePtyWrapper must not turn it into a skip.
   assert.throws(
     () =>