feat(docker): readable names, CPU in cores and memory in bytes, failures listed with since-times (#5209)

#5209 "Docker views: readable names, CPU/memory in cores and bytes, failures
listed with since-time" (milestone 477 "UI problems first").

- A swarm task reads as its service and slot ("codex_db · 1", or the node
  for a global service), with the raw name in the title: Docker page, host
  panel, busiest widget, container detail.
- CPU reads in cores (Docker's 100% = one core), toned by its share of the
  host's CPUs from the agent's per-core series. Memory reads in bytes, against
  a limit only when one is really set (Docker reports host RAM otherwise).
- Exit 137/143 without an OOM kill is a stop, not a failure: no
  exited_nonzero, no crash-loop death, no "failed (24h)", dim exit code.
- "Failed (24h)" is a list (Docker page #failures, linked from the widget
  and the tile): plain containers by their deaths, swarm services by Swarm's
  failed tasks; a second manager's copy of a task death counts once.
- Failing swarm services lead Needs attention; services sort problems first
  with since-times on the page, the widget and the Swarm page; nodes that
  are down or drained sort first.
- Busiest widget orders by a 5-minute CPU average so the list holds still.
- Host panel: a table, problems first with what is wrong and since when;
  replaced swarm tasks hidden and counted.
- Container detail: node hostname, I/O labelled "since start", Restarts
  hidden for swarm tasks with a note on where task failures are.
- Widget names: "Docker — Services & failures", "Docker — Busiest containers".

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

steward/core/widgets.py

@@ -209,8 +209,8 @@ WIDGET_REGISTRY: dict[str, dict] = {
     },
     "docker_containers": {
         "key": "docker_containers",
-        "label": "Docker — Containers",
-        "description": "Container status overview — running/stopped counts and per-container CPU",
+        "label": "Docker — Services & failures",
+        "description": "What Docker is running and what failed: swarm services and containers, problems first, with the last 24h's failures",
         "hx_url": "/plugins/docker/widget",
         "detail_url": "/plugins/docker/",
         "plugin": "docker",
@@ -230,8 +230,8 @@ WIDGET_REGISTRY: dict[str, dict] = {
     },
     "docker_resources": {
         "key": "docker_resources",
-        "label": "Docker — Resources",
-        "description": "CPU and memory usage bars for running containers",
+        "label": "Docker — Busiest containers",
+        "description": "The containers using the most CPU (cores, 5-minute average) and their memory",
         "hx_url": "/plugins/docker/widget/resources",
         "detail_url": "/plugins/docker/",
         "plugin": "docker",