feat(chat): render commercial actions and persist greetings

src/app/chat/components/chat-area.module.css

@@ -131,6 +131,64 @@
   align-items: flex-end;
 }
 
+.commercialAction {
+  width: min(100%, 286px);
+  padding: 12px;
+  border: 1px solid rgba(255, 255, 255, 0.18);
+  border-radius: 8px;
+  background: rgba(25, 21, 31, 0.92);
+  box-shadow: 0 10px 24px rgba(0, 0, 0, 0.2);
+}
+
+.commercialActionHeader {
+  display: flex;
+  min-height: 24px;
+  align-items: center;
+  justify-content: space-between;
+  color: #f4b860;
+}
+
+.commercialActionDismiss {
+  display: inline-flex;
+  width: 28px;
+  height: 28px;
+  align-items: center;
+  justify-content: center;
+  border: 0;
+  background: transparent;
+  color: rgba(255, 255, 255, 0.66);
+  cursor: pointer;
+}
+
+.commercialActionCopy {
+  margin: 7px 0 11px;
+  color: rgba(255, 255, 255, 0.9);
+  font-size: var(--responsive-caption, var(--font-size-sm, 13px));
+  line-height: 1.45;
+}
+
+.commercialActionButton {
+  display: inline-flex;
+  min-height: 38px;
+  max-width: 100%;
+  align-items: center;
+  justify-content: center;
+  gap: 7px;
+  padding: 8px 12px;
+  border: 0;
+  border-radius: 6px;
+  background: #f4b860;
+  color: #201710;
+  cursor: pointer;
+  font-size: var(--responsive-caption, var(--font-size-sm, 13px));
+  font-weight: 700;
+}
+
+.commercialActionButton span {
+  min-width: 0;
+  overflow-wrap: anywhere;
+}
+
 .bubbleAi {
   max-width: var(--chat-bubble-max-width, 75%);
   background: var(--color-bubble-ai, rgba(255, 255, 255, 0.08));