feat(FN-2685): remove TaskCard token usage badge

- Remove token usage badge rendering and compact token formatting from TaskCard
- Drop token usage fields from TaskCard memo equality checks now that the badge is gone
- Delete obsolete TaskCard token badge CSS rules and icon import
- Simplify TaskCard tests by removing token badge assertions and related fixtures

packages/dashboard/app/components/TaskCard.css

@@ -478,21 +478,6 @@
   opacity: 0.7;
 }
 
-.card-token-usage {
-  display: inline-flex;
-  align-items: center;
-  gap: var(--space-xs);
-  color: var(--text-muted);
-  font-size: calc(var(--space-sm) + var(--space-xs) * 0.75);
-  line-height: 1;
-  white-space: nowrap;
-}
-
-.card-token-usage-value {
-  font-family: var(--font-mono);
-  font-weight: 600;
-}
-
 .card-time-indicator {
   display: inline-flex;
   align-items: center;
@@ -1004,10 +989,6 @@
     gap: var(--space-xs);
   }
 
-  .card-token-usage {
-    font-size: calc(var(--space-sm) + var(--space-xs) * 0.5);
-  }
-
   .card-time-indicator {
     padding: var(--space-xs) var(--space-sm);
     font-size: 10px;