fix: add inter-retry delay for UNAVAILABLE errors in StatusMonitor poll loop

Remove the `continue` statement from the UNAVAILABLE handler in
_poll_loop so it falls through to the standard sleep block. Previously,
UNAVAILABLE retries had no delay between attempts, so 10 retries could
be exhausted in under 1ms -- far too fast to tolerate an exporter
restart that takes several seconds. Now retries use the poll_interval
sleep, making the 10-retry threshold span a meaningful duration.

Generated-By: Forge/20260416_202053_681470_11575359_i242
Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: raballew

python/packages/jumpstarter/jumpstarter/client/status_monitor.py

@@ -406,7 +406,6 @@ async def _poll_loop(self):  # noqa: C901
                         logger.warning("GetStatus UNAVAILABLE %d times consecutively", unavailable_retries)
                     else:
                         logger.debug("GetStatus UNAVAILABLE (attempt %d), retrying...", unavailable_retries)
-                    continue
                 elif e.code() == StatusCode.DEADLINE_EXCEEDED:
                     # DEADLINE_EXCEEDED is a transient error (RPC timed out), not a
                     # permanent connection loss. Keep polling - the shell's own timeout

python/packages/jumpstarter/jumpstarter/client/status_monitor_test.py

@@ -810,6 +810,39 @@ async def test_wait_for_any_of_updates_status_message(self) -> None:
         assert monitor.status_message == "hook script exited with code 1"
 
 
+class TestStatusMonitorUnavailableRetryDelay:
+    async def test_unavailable_retries_include_inter_retry_delay(self) -> None:
+        """Test that UNAVAILABLE retries sleep between attempts.
+
+        Without inter-retry delay, 10 UNAVAILABLE errors (which return
+        near-instantly) would be exhausted in milliseconds, providing
+        no time for an exporter to restart. The poll loop must sleep
+        between UNAVAILABLE retries so the threshold spans a meaningful
+        wall-clock duration.
+        """
+        import time
+
+        retry_count = 10
+        poll_interval = 0.05
+        responses = [
+            create_mock_rpc_error(StatusCode.UNAVAILABLE)
+            for _ in range(retry_count)
+        ]
+        stub = MockExporterStub(responses, repeat_last=False)
+        monitor = StatusMonitor(stub, poll_interval=poll_interval)
+
+        start = time.monotonic()
+        await monitor.start()
+        elapsed = time.monotonic() - start
+
+        assert monitor.connection_lost
+        minimum_expected = poll_interval * (retry_count - 1)
+        assert elapsed >= minimum_expected, (
+            f"UNAVAILABLE retries completed in {elapsed:.3f}s, "
+            f"expected at least {minimum_expected:.3f}s with inter-retry delay"
+        )
+
+
 class TestStatusMonitorPRIssues:
     """Regression tests for issues reported during PR review of hooks feature."""