feat(helpdesk): replace abstract driver bars with concrete reason texts

Cards now show plain-language reasons instead of abstract progress bars:
'8 open, 3 critical', '↑4 more than resolved', '2 SLA breaches',
'Oldest ticket 12d'. Instantly understandable without knowing the
scoring formula. Driver bars remain in the detail dialog for the
full dimension breakdown.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

modules/helpdesk/web/css/helpdesk.css

@@ -630,22 +630,15 @@
     font-weight: 600;
   }
 
-  .helpdesk-risk-card-drivers {
-    display: grid;
-    gap: calc(var(--app-spacing) * 0.2);
-  }
-
-  .helpdesk-risk-card-driver {
-    display: flex;
-    align-items: center;
-    gap: calc(var(--app-spacing) * 0.35);
+  .helpdesk-risk-card-reasons {
+    list-style: none;
+    margin: 0;
+    padding: 0;
     font-size: var(--text-xs, 0.75rem);
-  }
-
-  .helpdesk-risk-card-driver-label {
-    min-width: 7ch;
     color: var(--app-muted-color);
-    flex-shrink: 0;
+    display: flex;
+    flex-direction: column;
+    gap: 0.15em;
   }
 
   .helpdesk-risk-card-driver-bar {