feat(norms): hosts, containers and monitor response times are graded against their own normal (#5742)

Host CPU, memory and load per core, container CPU and memory, and every
monitor's response time learn a normal per hour (milestone 513, System 182).
A reading past its fixed cutoff but within its normal reads healthy and says
what is usual at this hour; one well out of it keeps its grade and is a
metric anomaly. Disk, a monitor down and an agent offline keep their cutoffs.

- Each normal's floor, the smallest departure that counts, is a setting:
  Settings -> Thresholds -> Normals (norms.floor.*). Defaults: host CPU 10
  points, host memory 5, load per core 10, container CPU 10 points of one
  core, container memory 5, monitor response 100 ms; Traefik's 2-point 4xx
  and 50 ms p95 floors move there from constants. learn_normal takes a
  floor function (floor_setting) read at each pass.
- learn_normal(parts=False): a host learns, its cores don't.
- Ingest records load_pct (load_1m / cores x 100), the figure pages grade.
- Shared grading: anomalies.against / graded, worst_reading(normals=),
  hosts' host_grades, docker usage(thresholds=, norms=), monitors'
  latency_grade. Applied to host vitals, the Hosts widget, MCP overview,
  Docker usage, and the monitor list, widget and page.
- The monitor and container pages list their anomalies.

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

plugins/host_agent/__init__.py

@@ -11,6 +11,14 @@ _app: "Quart | None" = None
 def setup(app: "Quart") -> None:
     global _app
     _app = app
+    # A host's CPU, memory and load per core learn their normal (#5742), each
+    # with its floor from Settings → Thresholds. Parts don't: a host's CPU has
+    # a normal, each of its cores doesn't. Disks stay on their fixed cutoffs:
+    # a nearly full disk is a failure whatever its history (System 182).
+    from steward.core.norms import floor_setting, learn_normal
+    learn_normal("host_agent", "cpu_pct", floor_setting(app, "host_cpu_pct"), parts=False)
+    learn_normal("host_agent", "mem_used_pct", floor_setting(app, "host_mem_pct"), parts=False)
+    learn_normal("host_agent", "load_pct", floor_setting(app, "host_load_pct"), parts=False)
 
 
 def get_scheduled_tasks() -> list:
@@ -38,9 +46,10 @@ def get_alert_metrics() -> dict[str, list[str]]:
     disk_used_pct per mount, resource "<host>:<mount>"). seconds_since_seen
     comes from the scheduler, not the agent: "agent offline" is > 180.
     clock_off_secs is how far the host's clock is from Steward's, either way
-    (agent ≥ 1.12.0): "clock drifting" is > 30."""
+    (agent ≥ 1.12.0): "clock drifting" is > 30. load_pct is load_1m as a %
+    of the host's cores."""
     return {"host_agent": [
         "cpu_pct", "mem_used_pct", "mem_available_bytes", "swap_used_bytes",
-        "disk_used_pct_worst", "disk_used_pct", "load_1m", "load_5m", "load_15m",
+        "disk_used_pct_worst", "disk_used_pct", "load_1m", "load_5m", "load_15m", "load_pct",
         "uptime_secs", "seconds_since_seen", "clock_off_secs",
     ]}