Add campaign UTM links and piha.li shortener as a core helper.

Keep mint/UTM in always-on core so email_sms and directmail stay optional, and brand utm_source from SITE_NAME (or UTM_SOURCE) instead of a hardcoded client name.
Closes #3

site/client_site/static/css/portal.css

@@ -690,3 +690,39 @@ body.portal {
   padding: 8px 10px; border: 1px solid var(--monica-border); font: inherit; font-size: 13px; background: #fff;
 }
 .empty-state { padding: 24px; color: var(--monica-muted); font-size: 14px; }
+
+.utm-panel {
+  margin-top: 4px;
+  padding-top: 4px;
+}
+.utm-url {
+  display: block;
+  font-size: 12px;
+  line-height: 1.45;
+  word-break: break-all;
+  background: #f8fafc;
+  border: 1px solid var(--monica-border);
+  padding: 8px 10px;
+  color: #0f172a;
+}
+.utm-actions {
+  display: flex;
+  gap: 8px;
+  flex-wrap: wrap;
+  margin-top: 8px;
+}
+.utm-qr {
+  display: flex;
+  gap: 16px;
+  align-items: flex-start;
+  flex-wrap: wrap;
+  margin-top: 12px;
+}
+.utm-qr canvas {
+  display: block;
+  border: 1px solid var(--monica-border);
+  background: #fff;
+}
+.utm-qr-actions { min-width: 160px; }
+.utm-qr-actions .btn { margin: 0 8px 8px 0; }
+#preview-body a { color: var(--monica-primary); }