feat(docker): the service and container pages say each fact once (#5310)

Service page:
- The header carries the verdict, mode, stack, image and when it was reported.
  'In trouble since' shows only while the service is in trouble; once recovered,
  'Last failed X ago · its logs'.
- The failure card shows only while the service is down, degraded or crash-looping.
- The tile strip and the kv card are gone.
- One Tasks table: running tasks first with CPU, memory and since when, then
  Swarm's record. The node is named as its Steward host throughout, and
  'N failed in 24h' sits in the caption.

Container page:
- Same shape: header verdict, a 'Last exit' card only while it is stopped
  after a failing exit, set-up and I/O in one kv card, and lifecycle as a table.
- A swarm task's breadcrumb goes through its service.

Both pages:
- Resource history is the one fragment (_usage_history.html): now and peak in
  cores and bytes, drawn with a floor of 1 core / 1 GiB (sparkline_svg floor=),
  so idle noise draws flat.
- The container page's old % sparklines, its private _sparkline and the unused
  bucket()/container_history() helpers are removed.

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

tests/core/test_status.py

@@ -78,3 +78,15 @@ def test_a_sparkline_can_stretch_across_its_tile():
     assert 'vector-effect="non-scaling-stroke"' in wide
     fixed = sparkline_svg([1, 2, 3])
     assert 'width="80"' in fixed and "preserveAspectRatio" not in fixed
+
+
+def test_a_sparkline_with_a_floor_draws_idle_noise_flat():
+    """#5310: 0.01 → 0.09 cores against a 1-core floor stays near the bottom;
+    without it the same wobble fills the height. A peak above the floor is
+    the top, and the line starts from zero."""
+    def ys(svg):
+        pts = svg.split('points="')[1].split('"')[0].split()
+        return [float(p.split(",")[1]) for p in pts]
+    assert ys(sparkline_svg([0.01, 0.09])) == [19.0, 1.0]
+    assert ys(sparkline_svg([0.01, 0.09], floor=1.0)) == [18.8, 17.4]
+    assert ys(sparkline_svg([1.0, 2.0], floor=1.0)) == [10.0, 1.0]