feat: add icon button component and integrate into cart item for improved UI

src/app/shared/components/icon-button/icon-button.component.scss

@@ -0,0 +1,64 @@
+:host {
+  display: inline-block;
+  vertical-align: middle;
+}
+
+.icon-btn {
+  display: inline-flex;
+  align-items: center;
+  justify-content: center;
+  background: transparent;
+  border: none;
+  padding: 4px;
+  margin: 0;
+  color: #666666;
+  font-size: 20px;
+  cursor: pointer;
+  outline: none;
+  transition: color 0.15s ease-in-out, transform 0.1s ease-in-out;
+  border-radius: 4px;
+
+  i {
+    display: inline-block;
+    line-height: 1;
+  }
+
+  // Active state subtle scale down
+  &:active:not(:disabled) {
+    transform: scale(0.92);
+  }
+
+  // Focus ring for accessibility
+  &:focus-visible {
+    outline: 2px solid var(--tenant-primary);
+    outline-offset: 2px;
+  }
+
+  // Disabled state
+  &:disabled {
+    color: #A0A0A0;
+    cursor: not-allowed;
+    pointer-events: none;
+  }
+}
+
+// Hover/Active/Focus colors (non-disabled)
+.icon-btn:hover:not(:disabled),
+.icon-btn:focus-visible:not(:disabled),
+.icon-btn.hover-preview:not(:disabled),
+:host(.hover-preview) .icon-btn:not(:disabled) {
+  color: var(--tenant-primary);
+}
+
+// Trash is special (uses danger color for hover/active)
+.icon-btn--trash {
+  &:hover:not(:disabled),
+  &:focus-visible:not(:disabled),
+  &.hover-preview:not(:disabled) {
+    color: var(--tenant-danger);
+  }
+}
+
+:host(.hover-preview) .icon-btn--trash:not(:disabled) {
+  color: var(--tenant-danger);
+}