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/templates/_host_vitals.html

@@ -1,6 +1,7 @@
 {# Host health header — live polled into the host hub: live or stale, the worst
    reading against Settings → Thresholds, last seen, then CPU / memory / disk /
-   load tiles graded by the same cutoffs. Renders nothing until the agent
+   load tiles graded by the same cutoffs (`grades`; CPU, memory and load within
+   the host's own normal for the hour read healthy, and `usual` says so). Renders nothing until the agent
    reports (the Agent panel below then shows provisioning). #}
 {% from "_macros.html" import status_badge, stat_tile %}
 {% macro pct(v) %}{{ '%.0f%%'|format(v) if v is not none else '—' }}{% endmacro %}
@@ -11,6 +12,7 @@
     <span class="host-health-summary">
       {%- if stale %}No report since {{ reg.last_seen_at|ago }}; the readings below are from then.
       {%- elif worst %}<span class="tone-{{ worst[2] }}">{{ worst[0] }} {{ pct(worst[1]) }}</span> is past its {{ "critical" if worst[2] == "crit" else "warning" }} threshold.
+      {%- elif usual %}Every reading is within its thresholds or its usual level for this hour.
       {%- else %}Every reading is within its thresholds.{% endif -%}
     </span>
     <span class="problem-detail">
@@ -20,11 +22,14 @@
     </span>
   </div>
   <div class="stat-strip host-health-tiles" style="margin-bottom:0;">
-    {{ stat_tile("CPU", pct(cpu), state=status_class(cpu, 'cpu'), hint=sparks.cpu|safe) }}
-    {{ stat_tile("Memory", pct(mem), state=status_class(mem, 'mem'), hint=sparks.mem|safe) }}
-    {{ stat_tile("Disk /", pct(disk_root), state=status_class(disk_root, 'disk'), hint=sparks.disk|safe) }}
-    {{ stat_tile("Load per core", pct(load_per_core), state=status_class(load_per_core, 'load'), hint=sparks.load|safe) }}
+    {{ stat_tile("CPU", pct(cpu), state=grades.cpu[0], hint=sparks.cpu|safe) }}
+    {{ stat_tile("Memory", pct(mem), state=grades.mem[0], hint=sparks.mem|safe) }}
+    {{ stat_tile("Disk /", pct(disk_root), state=grades.disk[0], hint=sparks.disk|safe) }}
+    {{ stat_tile("Load per core", pct(load_per_core), state=grades.load[0], hint=sparks.load|safe) }}
   </div>
+  {% if usual and not stale %}
+  <p class="field-hint" style="margin-top:0.6rem;">{{ usual | join("; ") | capitalize }}.</p>
+  {% endif %}
   {% if psi.cpu is not none or psi.mem is not none or psi.io is not none %}
   <p class="field-hint" style="margin-top:0.6rem;" title="Pressure stall: the share of the last 10 s that tasks waited for the resource">
     Pressure (10 s): cpu {{ pct(psi.cpu) }} · mem {{ pct(psi.mem) }} · io {{ pct(psi.io) }}