Add auth foundation and app DB management

app/static/styles.css

@@ -83,6 +83,59 @@ a {
   color: var(--accent);
 }
 
+.auth-panel {
+  max-width: 520px;
+  margin-inline: auto;
+}
+
+.auth-form,
+.logout-form {
+  display: grid;
+  gap: 16px;
+}
+
+.auth-form label {
+  display: grid;
+  gap: 8px;
+  font-size: 0.95rem;
+  color: var(--muted);
+}
+
+.auth-form input {
+  width: 100%;
+  padding: 12px 14px;
+  border: 1px solid rgba(31, 41, 51, 0.14);
+  border-radius: 12px;
+  background: rgba(255, 255, 255, 0.92);
+  color: var(--text);
+  font: inherit;
+}
+
+button {
+  width: fit-content;
+  min-width: 120px;
+  padding: 12px 18px;
+  border: none;
+  border-radius: 999px;
+  background: var(--accent);
+  color: white;
+  font: inherit;
+  cursor: pointer;
+}
+
+button:hover {
+  filter: brightness(1.04);
+}
+
+.alert {
+  margin-bottom: 16px;
+  padding: 12px 14px;
+  border-radius: 12px;
+  background: rgba(157, 37, 37, 0.08);
+  border: 1px solid rgba(157, 37, 37, 0.14);
+  color: #8b2a2a;
+}
+
 @media (max-width: 640px) {
   .shell {
     margin: 24px auto;
@@ -92,4 +145,3 @@ a {
     padding: 24px;
   }
 }
-