Persist runtime config in app db and seed from env

app/static/styles.css

@@ -61,6 +61,11 @@ h1 {
   margin: 0;
 }
 
+.single-column {
+  grid-template-columns: minmax(180px, 320px);
+  margin-bottom: 24px;
+}
+
 .meta div {
   padding: 16px;
   border-radius: 16px;
@@ -136,6 +141,47 @@ button:hover {
   color: #8b2a2a;
 }
 
+.notice {
+  margin-bottom: 16px;
+  padding: 12px 14px;
+  border-radius: 12px;
+  background: rgba(45, 106, 79, 0.08);
+  border: 1px solid rgba(45, 106, 79, 0.14);
+  color: var(--accent);
+}
+
+.config-block + .config-block {
+  margin-top: 28px;
+}
+
+.config-block h2 {
+  margin: 0 0 16px;
+  font-size: 1.25rem;
+}
+
+.config-form {
+  display: grid;
+  gap: 20px;
+}
+
+.config-section {
+  margin: 0;
+  padding: 18px;
+  border: 1px solid rgba(31, 41, 51, 0.08);
+  border-radius: 16px;
+  display: grid;
+  gap: 14px;
+}
+
+.config-section legend {
+  padding: 0 8px;
+  color: var(--accent);
+}
+
+.config-form label small {
+  color: var(--muted);
+}
+
 @media (max-width: 640px) {
   .shell {
     margin: 24px auto;