Swap editor for Quill and add AI image insertion

public/css/site.css

@@ -269,3 +269,45 @@ article.card:hover {
   background: rgba(18, 24, 38, 0.06);
   color: var(--ink);
 }
+
+.editor-shell {
+  border: 1px solid rgba(18, 24, 38, 0.12);
+  border-radius: 1rem;
+  overflow: hidden;
+  background: #fff;
+}
+
+.rich-editor {
+  min-height: 320px;
+}
+
+.ql-toolbar.ql-snow {
+  border: 0;
+  border-bottom: 1px solid rgba(18, 24, 38, 0.10);
+  padding: 0.75rem;
+  background: #fbfaf7;
+}
+
+.ql-container.ql-snow {
+  border: 0;
+  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
+  font-size: 16px;
+}
+
+.ql-editor {
+  min-height: 320px;
+  padding: 1.25rem;
+  line-height: 1.7;
+}
+
+.ql-editor img {
+  max-width: 100%;
+  border-radius: 0.75rem;
+  box-shadow: 0 12px 30px rgba(18, 24, 38, 0.12);
+}
+
+.ql-toolbar .btn {
+  border-radius: 999px;
+  padding: 0.35rem 0.8rem;
+  font-size: 0.82rem;
+}