feat(host_agent): a temperature sensor is judged by how it moves against the CPU (#5783)

A board's spare thermistor inputs report whatever an open input reads, and
the value rule from #5759 only catches the impossible ones. Once an hour,
sensors.refresh judges each sensor against the host's CPU (Package id N,
Tctl/Tdie/TccdN, PECI Agent N) over a week of hourly averages. A sensor is
ruled out if it falls as the CPU warms (r <= -0.5) or holds within 0.5 °C
while the CPU moved 10 °C or more. A judgment needs at least 72 shared hours.

The host temperature leaves judged sensors out at ingest. The host page
lists them under "Not counted", with each reason given once.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

tests/plugins/host_agent/test_expand_metrics.py

@@ -162,7 +162,8 @@ def test_the_page_lists_unwired_sensors_apart_hottest_first():
     """VDNT-Util01's sensor list read SYSTIN 115 °C in red at the top, though
     the host's temperature already left it out (#5759)."""
     from plugins.host_agent.routes import split_temps
-    real, unwired = split_temps({"SYSTIN": 115.0, "AUXTIN0": 110.0, "Package id 0": 52.0,
-                                 "Composite": 48.9, "PCH_CHIP_TEMP": 0.0, "CPUTIN": 47.0, "gone": None})
+    real, unwired = split_temps("h", {"SYSTIN": 115.0, "AUXTIN0": 110.0, "Package id 0": 52.0,
+                                      "Composite": 48.9, "PCH_CHIP_TEMP": 0.0, "CPUTIN": 47.0, "gone": None})
     assert list(real) == ["Package id 0", "Composite", "CPUTIN", "gone"]
     assert list(unwired) == ["SYSTIN", "AUXTIN0", "PCH_CHIP_TEMP"]
+    assert unwired["SYSTIN"] == (115.0, "reads a value no wired sensor gives")