Dashboard cleanup: chart empty-state message, dead click-handler (#101)

Two small findings from the same dashboard audit pass:

1. Charts rendered a bare empty frame with no message when the
   filtered dataset was empty (fresh install, or a non-admin's
   visibility-filtered ticket set happening to be zero). makeDonut/
   makeBar now show a "No data for current filters" message in the
   chart's place instead of silently doing nothing.

2. Stat cards had two independent, redundant click-handler
   implementations. lt.statsFilter.init() (base.js, shared web_template
   code) read each card's data-filter-key/data-filter-val attributes
   and called window.lt_onStatFilter(key, val) on click — but that
   global is never defined anywhere in this app, so it only toggled a
   cosmetic .active class with no functional effect. The actual
   navigation logic is the separate handler at ~line 1282 that ignores
   those attributes entirely. Both fired on the same click with no
   visible symptom, but the markup looked load-bearing and wasn't — a
   trap for a future edit that touches one implementation assuming
   it's the only one. Removed the dead lt.statsFilter.init() call and
   the now-unused data-filter-key/data-filter-val attributes from this
   app's DashboardView.php (left the shared lt.statsFilter module in
   base.js itself untouched, since other LotusGuild apps consuming the
   same shared template file may define their own lt_onStatFilter).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01MGDKHiU5RJdo3dqQUDow3X

views/DashboardView.php

@@ -120,7 +120,6 @@ include __DIR__ . '/layout_header.php';
     ?>
 
   <div class="lt-stat-card stat-open" role="button" tabindex="0"
-       data-filter-key="status" data-filter-val="Open,Pending,In Progress"
        title="Click to filter by active tickets" aria-label="Open tickets">
     <div class="lt-stat-icon">[ # ]</div>
     <div class="lt-stat-info">
@@ -133,7 +132,6 @@ include __DIR__ . '/layout_header.php';
   </div>
 
   <div class="lt-stat-card stat-critical" role="button" tabindex="0"
-       data-filter-key="priority" data-filter-val="1"
        title="Click to filter critical (P1) tickets" aria-label="Critical P1 tickets">
     <div class="lt-stat-icon lt-text-danger">[ ! ]</div>
     <div class="lt-stat-info">
@@ -146,7 +144,6 @@ include __DIR__ . '/layout_header.php';
   </div>
 
   <div class="lt-stat-card stat-unassigned" role="button" tabindex="0"
-       data-filter-key="assigned_to" data-filter-val="unassigned"
        title="Click to filter unassigned tickets" aria-label="Unassigned tickets">
     <div class="lt-stat-icon lt-text-amber">[ @ ]</div>
     <div class="lt-stat-info">
@@ -171,7 +168,6 @@ include __DIR__ . '/layout_header.php';
   </div>
 
   <div class="lt-stat-card stat-resolved" role="button" tabindex="0"
-       data-filter-key="status" data-filter-val="Closed"
        title="Click to filter closed tickets" aria-label="Closed tickets today">
     <div class="lt-stat-icon lt-text-muted">[ OK ]</div>
     <div class="lt-stat-info">
@@ -334,7 +330,8 @@ include __DIR__ . '/layout_header.php';
 
   function makeDonut(canvasId, data, colorMap) {
     var ctx = document.getElementById(canvasId);
-    if (!ctx || !data.length) return;
+    if (!ctx) return;
+    if (!data.length) { showChartEmptyState(ctx); return; }
     ctx.title = 'Click a segment to filter the ticket list';
     return new Chart(ctx, {
       type: 'doughnut',
@@ -365,9 +362,22 @@ include __DIR__ . '/layout_header.php';
     });
   }
 
+  function showChartEmptyState(canvas) {
+    canvas.style.display = 'none';
+    var wrap = canvas.parentElement;
+    if (wrap && !wrap.querySelector('.lt-chart-empty')) {
+      var msg = document.createElement('div');
+      msg.className = 'lt-chart-empty';
+      msg.style.cssText = 'display:flex;align-items:center;justify-content:center;height:100%;color:var(--text-muted);font-size:0.75rem';
+      msg.textContent = 'No data for current filters';
+      wrap.appendChild(msg);
+    }
+  }
+
   function makeBar(canvasId, data) {
     var ctx = document.getElementById(canvasId);
-    if (!ctx || !data.length) return;
+    if (!ctx) return;
+    if (!data.length) { showChartEmptyState(ctx); return; }
     ctx.title = 'Click a bar to filter the ticket list';
     return new Chart(ctx, {
       type: 'bar',
@@ -1226,7 +1236,6 @@ window.TICKET_STATUSES = <?= json_encode($GLOBALS['config']['TICKET_STATUSES'])
 if (window.lt) {
     lt.keys.initDefaults();
     lt.tableNav.init('tickets-table');
-    lt.statsFilter.init();
 }
 
 // Saved filter pills — load on page init