feat(docker): Busiest Containers shows bars of the last hours beside each figure, scaled to the row's peak with a floor (#5214)

The fill bars were a share of the host's capacity, a sliver on hosts with
80 cores. Each figure now sits beside 24 bars of the last 6 hours (1h/24h
per widget), each row scaled to its own peak but never below 1 core or
1 GiB (configurable per widget), so a 0.05-core container reads flat and
a bar's height means real load. One grouped date_bin query feeds them.

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

steward/core/widgets.py

@@ -201,7 +201,7 @@ WIDGET_REGISTRY: dict[str, dict] = {
     "docker_resources": {
         "key": "docker_resources",
         "label": "Docker — Busiest containers",
-        "description": "The containers using the most CPU (cores, 5-minute average) and their memory",
+        "description": "The containers using the most CPU and memory, with bars of the last few hours",
         "hx_url": "/plugins/docker/widget/resources",
         "detail_url": "/plugins/docker/",
         "plugin": "docker",
@@ -218,6 +218,41 @@ WIDGET_REGISTRY: dict[str, dict] = {
                     {"value": 20, "label": "20 containers"},
                 ],
             },
+            {
+                "key": "hours",
+                "label": "Bars cover",
+                "type": "select",
+                "default": 6,
+                "options": [
+                    {"value": 1,  "label": "Last hour"},
+                    {"value": 6,  "label": "Last 6 hours"},
+                    {"value": 24, "label": "Last 24 hours"},
+                ],
+            },
+            {
+                "key": "cpu_floor",
+                "label": "CPU bars scale to at least",
+                "type": "select",
+                "default": 1.0,             # a float: the add form keeps fractions
+                "options": [
+                    {"value": 0.5, "label": "0.5 cores"},
+                    {"value": 1.0, "label": "1 core"},
+                    {"value": 2.0, "label": "2 cores"},
+                    {"value": 4.0, "label": "4 cores"},
+                ],
+            },
+            {
+                "key": "mem_floor",
+                "label": "Memory bars scale to at least",
+                "type": "select",
+                "default": 1.0,             # GiB
+                "options": [
+                    {"value": 0.25, "label": "256 MiB"},
+                    {"value": 1.0,  "label": "1 GiB"},
+                    {"value": 4.0,  "label": "4 GiB"},
+                    {"value": 16.0, "label": "16 GiB"},
+                ],
+            },
         ],
     },
     "snmp_devices": {