feat(dashboard): widget readability — name-per-line, fill graphs, container breakpoints

Address graphical issues raised from the dashboard screenshot:
- No more truncated host names. Hosts-Overview and Host-Agent-Resources put the
  host name on its own line (full, wraps if needed) with its data grouped beneath
  it; ping/dns (.ping-name) and uptime widget names wrap instead of ellipsis.
  Prefer vertical overflow over cramming/truncating a row.
- History graph fills the panel: drop the fixed 0–100 y-axis ceiling (beginAtZero
  + 8% grace) so the lines use the vertical space instead of hugging the bottom;
  axis labels still show real %.
- Container-query breakpoints: the widget body is now a query container, so
  fragments restyle to their OWN panel width. Host-list widgets flow into 2 cols
  ≥520px and 3 cols ≥900px (.host-blocks) — use the width, remove vertical
  deadspace — and collapse to one column when narrow. Mirrored into the share view.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

steward/templates/dashboard/share_view.html

@@ -44,7 +44,7 @@
     .ping-row { display:flex; align-items:center; gap:1rem; padding:0.45rem 0; border-bottom:1px solid var(--border); }
     .ping-row:last-child { border-bottom:none; }
     .ping-meta { min-width:120px; max-width:180px; flex-shrink:1; overflow:hidden; }
-    .ping-name { font-size:0.875rem; font-weight:500; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; display:block; }
+    .ping-name { font-size:0.875rem; font-weight:500; display:block; overflow-wrap:anywhere; }
     .ping-addr { display:block; color:var(--text-muted); font-size:0.75rem; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
     .ping-pills { display:flex; gap:2px; flex:1; min-width:0; overflow:hidden; align-items:center; }
     .pill { display:inline-block; width:7px; height:22px; border-radius:2px; }
@@ -59,6 +59,10 @@
     .dash-grid { display:grid; grid-template-columns:repeat(12,1fr); grid-auto-rows:70px; gap:1rem; }
     .dash-grid > .dash-cell { margin-bottom:0; min-width:0; overflow:hidden; display:flex; flex-direction:column; }
     .dash-cell .dash-cell-body { flex:1; min-height:0; overflow:auto; }
+    .dash-cell-body { container-type:inline-size; }
+    .host-blocks { display:grid; grid-template-columns:1fr; gap:0 1.5rem; }
+    @container (min-width:520px) { .host-blocks { grid-template-columns:1fr 1fr; } }
+    @container (min-width:900px) { .host-blocks { grid-template-columns:1fr 1fr 1fr; } }
     @media (max-width:820px) {
       .dash-grid { grid-template-columns:1fr; grid-auto-rows:auto; }
       .dash-grid > .dash-cell { grid-column:1 / -1 !important; grid-row:auto !important; }