fix(daytona): migrate legacy-sandbox lookup to cursor-based list() (#24587)

Daytona ships breaking SDK changes on June 10, 2026 — `list()` returns
an iterator and the `page=` offset parameter is removed. We pin
daytona==0.155.0 so we're past the May 24 hard-cutoff, but the
legacy-sandbox resume path in DaytonaEnvironment still passes `page=1`
and reads `.items` off the result.

Switch to `next(iter(results), None)` against a single-result
`list(labels=..., limit=1)` call. Update tests to use `iter([...])`
and drop the `page=1` kwarg from list() assertions.

tools/environments/daytona.py

@@ -101,9 +101,13 @@ class DaytonaEnvironment(BaseEnvironment):
 
             if self._sandbox is None:
                 try:
-                    page = self._daytona.list(labels=labels, page=1, limit=1)
-                    if page.items:
-                        self._sandbox = page.items[0]
+                    # Daytona SDK >=0.108.0 uses cursor-based pagination and
+                    # list() returns an iterator. Offset-based pagination
+                    # (page=1) is removed on June 10, 2026.
+                    results = self._daytona.list(labels=labels, limit=1)
+                    legacy = next(iter(results), None)
+                    if legacy is not None:
+                        self._sandbox = legacy
                         self._sandbox.start()
                         logger.info("Daytona: resumed legacy sandbox %s for task %s",
                                     self._sandbox.id, task_id)