laundry: fix four findings from the final review of guided setup

The one that could run the wrong program: guided setup accepted a name
another program already had. The duplicate check only compared names within
the form it was handed, and guided setup submits one program at a time, so
it never saw the others. Two programs sharing a label resolve to whichever
option comes first, so picking the second would have run the first one's
payload -- the exact failure the check exists to prevent, working correctly
in the bulk form and blind in the guided one. The taken set now includes
every other named program, excluding the slot being edited so confirming an
unchanged name doesn't reject itself.

The rest:

- The timeout screen's copy interpolates the same counters as the other two
  but was shown without placeholders, so it rendered literal braces.
- The probe reports whatever payload is loaded, while observe() declines one
  whose slot the device doesn't advertise. Guided setup could reach the name
  form for such a slot, take a name, and silently discard it -- there is no
  record to hang it on and no payload to replay. It now waits instead.
- The prefilled Download course came from the raw candidate list while the
  dropdown filters to courses the appliance still offers, so a stale
  candidate prefilled a value the selector rejects and the form failed
  validation on something the user never chose.

tests/test_cloud_courses_flow.py

@@ -709,3 +709,78 @@ async def test_guided_rejects_a_download_course_the_device_does_not_offer(hass:
     result = await handler.async_step_cloud_name({"name": "Sports", "download_course": "FF"})
     assert result["errors"] == {"base": "cloud_course_unknown_course"}
     assert coordinator.cloud_courses.snapshot()["download_course"] is None
+
+
+async def test_guided_rejects_a_name_another_program_already_has(hass: HomeAssistant):
+    """Guided setup submits one program at a time, so a within-form check
+    can't see the others. Two programs sharing a label resolve to whichever
+    option comes first, meaning picking the second would run the first one's
+    payload."""
+    coordinator = await _coordinator(hass)
+    coordinator.apply_cloud_courses({"6B": "Sports"}, "87")
+    await _flush(hass)
+
+    handler = await _options_handler(hass, coordinator)
+    await handler.async_step_cloud_guided()
+    _stub_probe(coordinator, ["55"])
+    await _run_wait(handler)
+
+    result = await handler.async_step_cloud_name({"name": "Sports"})
+    await _flush(hass)
+    assert result["errors"] == {"base": "cloud_course_name_duplicate"}
+    assert coordinator.cloud_courses.named() == {"6B": "Sports"}
+
+
+async def test_renaming_a_program_to_its_own_name_is_allowed(hass: HomeAssistant):
+    """The slot being edited is excluded from the taken set, or confirming an
+    unchanged name would reject itself."""
+    coordinator = await _coordinator(hass)
+    coordinator.apply_cloud_courses({"55": "Sports"}, "87")
+    await _flush(hass)
+
+    handler = await _options_handler(hass, coordinator)
+    await handler.async_step_cloud_guided()
+    _stub_probe(coordinator, ["55"])
+    await _run_wait(handler)
+
+    result = await handler.async_step_cloud_name({"name": "Sports"})
+    assert result["type"] == "progress"  # accepted, straight back to waiting
+
+
+async def test_the_timeout_screen_fills_in_its_counters(hass: HomeAssistant):
+    """Its copy interpolates the same placeholders as the other screens, so
+    without them the dialog renders literal braces."""
+    coordinator = await _coordinator(hass)
+    coordinator.apply_cloud_courses({"55": "Sports"}, "87")
+    await _flush(hass)
+
+    handler = await _options_handler(hass, coordinator)
+    result = await handler.async_step_cloud_timeout()
+    assert result["description_placeholders"]["named"] == "1"
+    assert result["description_placeholders"]["named_list"] == "Sports"
+
+
+async def test_guided_ignores_a_payload_the_store_would_not_record(hass: HomeAssistant):
+    """The probe reports whatever payload is loaded; observe() declines one
+    whose slot the device doesn't advertise. Offering to name that would take
+    a name and discard it -- there is no record to hang it on."""
+    coordinator = await _coordinator(hass)
+    handler = await _options_handler(hass, coordinator)
+    await handler.async_step_cloud_guided()
+
+    # 'ZZ' is not in this appliance's CloudExtraCourse_ list.
+    _stub_probe(coordinator, ["ZZ"])
+    result = await _run_wait(handler)
+    assert result["step_id"] == "cloud_timeout"
+
+
+async def test_the_prefilled_course_is_always_one_the_dropdown_offers(hass: HomeAssistant):
+    """An observed candidate the appliance's course list no longer contains
+    would prefill a value the selector rejects, failing validation on
+    something the user never chose."""
+    coordinator = await _coordinator(hass)
+    coordinator.cloud_courses._candidates["FF"] = 99  # not in the course list
+    handler = await _options_handler(hass, coordinator)
+
+    offered = handler._cloud_course_selector(coordinator).config["options"]
+    assert handler._cloud_course is None or handler._cloud_course in offered