Align downline rows into a grid (name | contact | date | action)

Each row was an independent flex line, so variable-width emails threw the date
column out of alignment across rows. Now a CSS grid with a shared template keeps
the date and Message columns lined up; long names/emails truncate; responsive
stack on narrow screens.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

public/assets/my.js

@@ -806,7 +806,7 @@
         '<div class="lin-lvl"><div class="cap">Level ' + L.level + ' · ' + L.members.length + (L.level === 1 ? ' direct' : '') + '</div>'
         + L.members.map(m => '<div class="lin-row"><span class="nm">' + esc(m.name) + '</span>'
           + (m.email ? '<span class="em">' + esc(m.email) + '</span>' : '<span class="id">#' + m.memberId + '</span>')
-          + '<span class="id" style="margin-left:auto">' + new Date(m.joined).toLocaleDateString() + '</span>'
+          + '<span class="dt">' + new Date(m.joined).toLocaleDateString() + '</span>'
           + (m.email ? '<button class="btn sec small chat-msg-btn" type="button" data-cemail="' + esc(m.email) + '" data-cname="' + esc(m.name) + '">Message</button>' : '')
           + '</div>').join('')
         + '</div>').join('');