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/hosts/uptime_widget.html

@@ -17,9 +17,9 @@
   <div style="display:grid;grid-template-columns:1fr 52px 52px 52px;gap:0.35rem;align-items:center;padding:0.15rem 0;font-size:0.82rem;">
     {% if session.user_id %}
     <a href="/hosts/{{ host.id }}" title="{{ host.name }}"
-       style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;color:inherit;text-decoration:none;">{{ host.name }}</a>
+       style="overflow-wrap:anywhere;color:inherit;text-decoration:none;">{{ host.name }}</a>
     {% else %}
-    <span style="white-space:nowrap;overflow:hidden;text-overflow:ellipsis;" title="{{ host.name }}">{{ host.name }}</span>
+    <span style="overflow-wrap:anywhere;" title="{{ host.name }}">{{ host.name }}</span>
     {% endif %}
     {% for window in ["24h", "7d", "30d"] %}
     {% set pct = ut.get(window) %}