test(flaky): ubicloud fake ssh dispatches on the remote command, not on a '-O' in the checkout name (GSTA-139)

The fake ssh's *-O* arm, meant for 'ssh -O exit' (whose last argument is the
host, so it never matched), caught any remote command whose path held '-O':
dest work/ubi-run-O????? whenever mkdtemp's first random character was O.
Sync then failed with exit 2 (tar child 141) or every phase exited 0, in about
1.3 s, before UBI_RUN_TIMEOUT could fire: Free Tests 40534568946 (:417, 2) and
40638411165 (:454, 0).

Co-authored-by: capy-ai[bot] <230910855+capy-ai[bot]@users.noreply.github.com>

test/ubicloud-runner.test.ts

@@ -391,7 +391,6 @@ describe('ubi-runner run, verify and quota against a fake API and a fake ssh', (
       'cmd=${*: -1}\n' +
       'printf \'%s\\n\' "$cmd" >> "$root/ssh.log"\n' +
       'case "$cmd" in\n' +
-      '  *-O*) exit 0 ;;\n' +
       '  *pkill*) echo "$cmd" >> "$root/cancel.log" ;;\n' +
       '  *captured*) cat > "$root/captured" ;;\n' +
       '  *"cat > ~/.ubirun-env"*) cat > "$root/ubirun-env" ;;\n' +
@@ -458,6 +457,18 @@ describe('ubi-runner run, verify and quota against a fake API and a fake ssh', (
     } finally { rmSync(f.root, { recursive: true, force: true }); }
   }, 60_000);
 
+  test('run: the fake ssh dispatches on the remote command, so a checkout whose name holds -O still syncs and runs (GSTA-139)', () => {
+    const f = fakeVm();
+    try {
+      const checkout = join(f.root, 'ubi-run-O1x2y3');
+      mkdirSync(checkout);
+      const r = run(f, ['run', '--src', checkout, '--', 'make test']);
+      expect(r.exitCode, r.stderr.toString()).toBe(0);
+      expect(r.stdout.toString()).toContain('ran: ');
+      expect(f.ssh()).toContain('tar -xzf - -C work/ubi-run-O1x2y3');
+    } finally { rmSync(f.root, { recursive: true, force: true }); }
+  }, 60_000);
+
   test('run: --pass forwards a named local variable only; UBICLOUD_* and non-names are refused before any API call', () => {
     const f = fakeVm();
     try {