fix(panel): keep the party-board hint clear of the dock

The hint line is a <p> whose user-agent 1em top margin was never reset,
so at 1920x1080 its box rendered at ~954-988px, under the dock (top edge
950px). Reset the margin, restore the PANEL-SPEC §2 27px/600 size, and
move the hint up to top: 896px so its 37.8px line box ends at ~934px,
16px above the dock. The dock keeps its 84px height and 46px inset.

Add a source-level regression test asserting the hint's margin reset
and that top + font-size x line-height sits at least 12px above
1080 - dock bottom - dock height.

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

custom_components/nestquest/www/nestquest-cards.js

@@ -906,11 +906,12 @@ const $t = "polygon(0 0, 100% 0, 100% 62%, 50% 100%, 0 62%)", $e = "polygon(50%
 
   .hint {
     position: absolute;
-    top: 930px;
+    top: 896px;
     left: 0;
     right: 0;
+    margin: 0;
     font-family: var(--nq-p-font-body);
-    font-size: 24px;
+    font-size: 27px;
     font-weight: 600;
     line-height: 1.4;
     text-align: center;